Dave Roos
Dave Roos is a freelance writer based in the United States and Mexico. A longtime contributor to HowStuffWorks, Dave has also been published in The New York Times, the Los Angeles Times and Newsweek.
Articles From This Author
10 of the Most Consequential Executive Orders and Proclamations in Presidential History
Executive orders aren’t mentioned once in the U.S. Constitution, but presidents starting with George Washington have used executive orders and proclamations in order to bypass Congress and quickly exercise the independent power of their office. Franklin D. Roosevelt is the ...read more
Steps the Supreme Court Takes to Reach a Decision
When the Supreme Court of the United States agrees to hear a case, the only part of the process that’s open to the public are the oral arguments. The rest of the deliberations happen behind closed doors between the nine justices and their teams of law clerks. So how exactly do ...read more
How Germany Was Divided After World War II
When the Allies celebrated Victory in Europe (VE) Day on May 8, 1945, the British military commander Bernard Law Montgomery cautioned his troops, “We have won the German war. Let us now win the peace.” Months before Germany’s unconditional surrender in World War II, the “Big ...read more
How Was the US Involved in WWII Before Pearl Harbor?
By the mid-1930s, the rise of Adolf Hitler’s Nazi Party in Germany threatened to engulf Europe into another world war. The United States, meanwhile, had taken an isolationist turn, with Americans refusing to send more young men to die on foreign battlefields. More than 100,000 ...read more
Why Did Stalin Support the Start of the Korean War?
The Korean War (1950-1953) was the first armed conflict of the Cold War era, and historians agree that communist North Korea would not have invaded South Korea in 1950 without the approval of Joseph Stalin, the ruthless and autocratic leader of the Soviet Union from 1922 to 1953. ...read more
Why So Many Foreign Nationals Volunteered to Fight in the Spanish Civil War
In July of 1936, a failed military coup plunged Spain into civil war. The conflict pitted the leftist Republican government against fascist-backed Nationalists led by General Francisco Franco. With Adolf Hitler and Benito Mussolini already in power in Germany and Italy, ...read more
The Harrowing Rescue Missions to Save the Donner Party Survivors
On October 20, 1846, an exceptionally early and heavy snowstorm dumped foot after foot of cement-like snow on the Sierra Nevada mountains, trapping 81 members of the ill-fated Donner Party, more than half of them children. Their five-month ordeal is one of the most infamous in ...read more
How Airplanes Were Used in World War I
The airplane had existed for little more than a decade by the outbreak of World War I, but both sides of the conflict quickly recognized the advantages of creating flying war machines and worked relentlessly throughout the war to develop faster, bigger and deadlier fighters and ...read more
How Nixon's 1972 Visit to China Changed the Balance of Cold War Power
On July 15, 1971, President Richard Nixon addressed the nation in a live televised broadcast to make an unexpected announcement: he had accepted an invitation from Beijing to become the first U.S. president to visit the People’s Republic of China, a Communist nation of 750 ...read more
How Many Times Has the US Officially Declared War?
The United States has officially declared war 11 times during five separate military conflicts. According to the Constitution (Article I, Section 8), Congress has the exclusive power to declare war. The last time America declared war was during World War II. The Korean War, the ...read more
How the Union Defended Washington, D.C. During the Civil War
When the Civil War broke out in 1861, Washington, D.C. remained the capital of the fractured United States and also the military headquarters of the Union Army. Richmond, the newly minted capital of the Confederacy, was less than 100 miles away in neighboring Virginia. Likening ...read more
How Christmas Was Celebrated in the Middle Ages
Long before Santa Claus, caroling and light-strewn Christmas trees, people in medieval Europe celebrated the Christmas season with 12 full days of feasting and revelry culminating with Twelfth Night and the raucous crowning of a “King of Misrule.” Christmas in the Middle Ages ...read more
How Justice John Marshall Expanded the Power of the Supreme Court
When John Marshall was appointed chief justice of the U.S. Supreme Court in 1801, the nation’s highest court occupied a lowly position. There was no Supreme Court Building in the newly completed capital, Washington, D.C., so the six justices heard cases in a borrowed room in the ...read more
How the Troubles Began in Northern Ireland
For 30 years, Northern Ireland was scarred by a period of deadly sectarian violence known as “the Troubles.” This explosive era was fraught with car bombings, riots and revenge killings that ran from the late 1960s through the late 1990s. The Troubles were seeded by centuries of ...read more
Before JFK, Lee Harvey Oswald Tried to Assassinate a Former Army General
On April 10, 1963, just seven months before he shot and killed President John F. Kennedy, the inscrutable assassin Lee Harvey Oswald crouched behind a fence in an upscale Dallas neighborhood and aimed his rifle at the window of an ultra-conservative firebrand named Edwin Walker, ...read more
7 Foods Developed by Native Americans
When Christopher Columbus reached the Americas, he hoped the land would be rich with gold, silver and precious spices, but perhaps the New World’s greatest treasure was its bounty of native food crops cultivated for millennia by Indigenous Americans. As much as three-fifths of ...read more
How Colin Powell's Service in Vietnam Shaped His Leadership
On November 16, 1968, Major Colin Luther Powell was serving his second tour of duty in Vietnam, this time as the assistant Chief of Staff to the commander of the U.S. Army’s Americal Division (also called the 23rd Infantry Division). It was mostly a desk job, but that day Powell ...read more
7 Famous Loyalists of the Revolutionary War Era
In a way, the American Revolution was also a civil war. By 1774, American colonists were divided into two camps: patriots and loyalists. Hotheaded patriots like the Sons of Liberty wanted to rid themselves of British rule at all costs. While the loyalists, either through stubborn ...read more
The Silk Road: 8 Goods Traded Along the Ancient Network
The Silk Road wasn’t a single route, but rather a vibrant trade network that crisscrossed central Eurasia for centuries, bringing far-flung cultures into contact. Traveling by camel and horseback, merchants, nomads, missionaries, warriors and diplomats not only exchanged exotic ...read more
How the End of the Vietnam War Led to a Refugee Crisis
On April 29, 1975, as communist North Vietnamese troops closed in on the South Vietnamese capital of Saigon, the United States ordered the immediate evacuation of U.S. personnel and several thousand South Vietnamese military and diplomatic officials. TV news cameras broadcasted ...read more
How Paul Revere's Engraving of the Boston Massacre Rallied the Patriot Cause
Paul Revere is best-known for his “midnight ride” celebrated in Henry Wadsworth Longfellow’s 1860 poem. But Revere’s role in the American Revolution extends far beyond that famous 1775 mission to warn the towns of Lexington and Concord that British troops were on the move from ...read more
8 Bronze Age Weapons
European archeologists have uncovered hoards of Bronze Age weaponry dating from more than 4,000 years ago. Some of the larger and more elaborate weapons—like the 28-inch dagger known as the Oxborough Dirk—may have been ceremonial or prestige pieces, but others show clear markings ...read more
The Patriot Financier Who Bankrolled the Revolutionary War
Without Robert Morris, the American Revolution may have been crushed under a mountain of debt and disarray. The self-made millionaire from Philadelphia never set out to be a politician, but was pressed into service by the Continental Congress when it needed a brash and savvy ...read more
What Caused the Bronze Age Collapse?
More than 3,200 years ago, the Mediterranean and Near East were home to a flourishing and interconnected Bronze Age civilization fueled by lucrative trade in valuable metals and finished goods. The great kingdoms and empires of the day—including the Egyptians, Babylonians, ...read more
How Early Humans Survived the Ice Age
The most recent ice age peaked between 24,000 and 21,000 years ago, when vast ice sheets covered North America and northern Europe, and mountain ranges like Africa's Mt. Kilimanjaro and South America's Andes were encased in glaciers. At that point our Homo sapien ancestors had ...read more
Wimbledon Served as a Military Camp and Pig Farm During World War II
For 75 years, active-duty members of the British military have served as stewards at Wimbledon, the annual tennis “Championships” held at the storied All England Lawn Tennis & Croquet Club. Since 1946, uniformed men and women from the Army, Air Force and Navy have volunteered at ...read more
How the Battle of Tannenberg Emboldened German Forces at the Start of World War I
There have been two epic battles at the place known as Tannenberg. The first, in 1410, saw the defeat of a German religious order called the Teutonic Knights at the hands of Slavs and Lithuanians. Five hundred years later, Germany got its revenge in one of the earliest battles ...read more
‘Blood in the Water’: The Cold War Olympic Showdown Between Hungary and the USSR
There are two layers to every water polo match: the graceful athleticism above the water, and the rough play and cheap shots hidden beneath the surface. The 1956 Melbourne Olympics were a lot like a game of water polo. On the surface, they were billed as the “friendly games,” but ...read more
'Miracle on Ice': When the US Olympic Hockey Team Stunned the World
The Soviet hockey team, led by an iron curtain of a goaltender named Vladislav Tretiak, was the clear favorite to bring home the gold at the 1980 Winter Olympics in Lake Placid, New York. The Soviets had won all four of the previous Olympics and had beaten the USA in all 12 ...read more
5 of the Most Significant Impact Craters in North America
There are roughly 180 known impact craters worldwide and fully a third of them—including some of the biggest—are located in North America. These massive blast zones were formed by meteors, asteroids and comets that slammed into the earth’s surface with a force many times greater ...read more
Cicada Swarms Were Documented by a Black Naturalist in the 18th Century
In the spring of 1749, the billions-strong swarm of cicadas known today as Brood X emerged from the ground in rural Maryland, much to the fascination (and horror) of a 17-year-old Black tobacco farmer named Benjamin Banneker, who believed they were a plague of locusts. “The ...read more
5 of History's Deadliest Bear Attacks
Few animals command as much respect and instill as much healthy fear as bears. While fatal bear attacks are rare—there have only been around 180 deaths from bear attacks in North America since the late 1700s—they never fail to shock with their brutality. The following list is ...read more
How the Shocking Use of Gas in World War I Led Nations to Ban It
At the dawn of the 20th century, the world’s military powers worried that future wars would be decided by chemistry as much as artillery, so they signed a pact at the Hague Convention of 1899 to ban the use of poison-laden projectiles "the sole object of which is the diffusion of ...read more
WWI's Battle of Messines: How Allies Used Massive Explosives and Tunneling to Win
The Western Front of World War I is infamous for trench warfare, long and grueling battles fought from dug-in positions separated by no man’s land. But a lesser-known type of battle also raged underground as both Allied and German forces dug extensive networks of secret tunnels ...read more
Presidential Succession: How the 'Designated Survivor' Fits In
Who succeeds the president in the event of death or incapacity? There’s a list of nearly 20 officials—starting with the vice president and the speaker of the House—whose top leadership roles place them squarely in line for the job. Then there’s the wild card: a “designated ...read more
The First ‘Vaccine Passports’ Were Scars from Smallpox Vaccinations
At the turn of the 20th century, the United States was in the grip of a full-blown smallpox epidemic. During the five-year outbreak from 1899 to 1904, government health officials confirmed 164,283 cases of smallpox, but the real numbers may have been five times as high. To slow ...read more
How the Erie Canal Was Built With Raw Labor and Amateur Engineering
In 1809, when President Thomas Jefferson reviewed New York’s ambitious plans for a more than 360-mile canal connecting the Hudson River (and therefore New York Harbor) to the Great Lakes, he dismissed it as “little short of madness” and refused to authorize federal funding. Less ...read more
8 Facts About the Celts
To modern ears, the word “Celtic” evokes traditional art, literature and music from Ireland and Scotland. But the ancient Celts were a widespread group of people with origins in central Europe. See what historians have learned about this rich and complex collection of tribes. 1. ...read more
How the Aztec Empire Was Forged Through a Triple Alliance
The Aztec Empire was a shifting and fragile alliance of three principal city-states. The largest and most powerful among the three was Tenochtitlán, the island city built by the Mexica people, also known as the Aztecs. The Aztec Triple Alliance exerted tremendous power over a ...read more
How Many US Presidents Have Faced Censure?
Since 1800, 14 sitting presidents have faced censure by either the Senate or the House of Representatives, but only a handful of those official rebukes were ever adopted by Congress, and the one that arguably stung the most was later “expunged” from the record. A censure is a ...read more
The 1969 Raid That Killed Black Panther Leader Fred Hampton
Early in the predawn hours of December 4, 1969, a Peoples Gas truck pulled up in front of an apartment building at 2337 W. Monroe St. in the West Side of Chicago. Fourteen plainclothes Chicago Police officers quietly filed out of the undercover truck, armed with pistols, a ...read more
The Deadliest Events in US History
It’s a grim calculation, counting those Americans who have died in service to their country, as targets of terrorist attacks, amid natural disasters or as victims of pandemic disease. Here are major events from history that have inflicted a devastating toll on American lives. 1. ...read more
Why the Whig Party Collapsed
In the mid-19th-century, the two most powerful political parties in the United States were the Democrats and the Whigs. In two presidential elections, 1840 and 1848, Americans voted a Whig into the White House. And some of the most prominent political voices of the contentious ...read more
When the Supreme Court Ruled a Vaccine Could Be Mandatory
In 1901 a deadly smallpox epidemic tore through the Northeast, prompting the Boston and Cambridge boards of health to order the vaccination of all residents. But some refused to get the shot, claiming the vaccine order violated their personal liberties under the Constitution. ...read more
7 Major Events That Happened During Lame Duck Sessions
Americans borrowed the term “lame duck” from the British, who first applied the insult to bankrupt businessmen in the 18th century and then to 19th-century politicians whose time in office was quickly running out. Before the 20th Amendment was ratified in 1933, lame-duck ...read more
Why the 1918 Flu Pandemic Never Really Ended
An unthinkable more than 50 million people worldwide died from the 1918-1919 flu pandemic commonly known as the “Spanish Flu.” It was the deadliest global pandemic since the Black Death, and rare among flu viruses for striking down the young and healthy, often within days of ...read more
9 Ancient Egyptian Weapons and Tools That Powered the Pharaoh's Army
The Egyptian military became one of the ancient world’s greatest fighting forces during the New Kingdom period (1550 B.C. - 1070 B.C.), but it did so using borrowed weapons technology. For much of its early history, Egypt relied on simple stone maces, wooden-tipped spears, axes ...read more
What Was Life Like Aboard the Mayflower?
Sailing for more than two months across 3,000 miles of open ocean, the 102 passengers of the Mayflower—including three pregnant women and more than a dozen children—were squeezed below decks in crowded, cold and damp conditions, suffering crippling bouts of seasickness, and ...read more
How Horses Transformed Life for Plains Indians
Forty million years ago, horses first emerged in North America, but after migrating to Asia over the Bering land bridge, horses disappeared from this continent at least 10,000 years ago. For millennia, Native Americans traveled and hunted on foot, relying on dogs as miniature ...read more
The Horrifying Discovery of Dachau Concentration Camp—And Its Liberation by US Troops
When the men of the 42nd “Rainbow” Division rolled into the Bavarian town of Dachau at the tail end of World War II, they expected to find an abandoned training facility for Adolf Hitler’s elite SS forces, or maybe a POW camp. What they discovered instead would be seared into ...read more