On February 12, 1909, the 100th anniversary of Abraham Lincoln's birth, a group that included African American leaders such as W.E.B. Du Bois and Ida B. Wells-Barnett announced the formation of a new organization. Called the National Association for the Advancement of Colored People, it would have a profound effect on the struggle for civil rights and the course of 20th-century American history.

On April 6, 1909, American explorer Robert Peary accomplishes a long elusive dream, when he, assistant Matthew Henson and four Inuits reach what they determine to be the North Pole. Decades after Peary’s death, however, navigational errors in his travel log surfaced, placing the expedition in all probability a few miles short of its goal.

On July 29, 1909, the newly formed General Motors Corporation (GM) acquires the country’s leading luxury automaker, the Cadillac Automobile Company, for $4.5 million.

On August 19, 1909, the first race is held at the Indianapolis Motor Speedway, now the home of the world’s most famous motor racing competition, the Indianapolis 500.

The Ballinger-Pinchot scandal erupts when Colliers magazine accuses Secretary of the Interior Richard Ballinger of shady dealings in Alaskan coal lands. It is, in essence, a conflict rooted in contrasting ideas about how to best use and conserve western natural resources.

On December 14, 1909, four months after tragedy struck at the Indianapolis Motor Speedway, race car drivers test out its newly resurfaced—and presumably safer—track. Workers had just finished laying down 3.2 million 10-pound brick pavers over the 2.5-mile oval, which had previously been covered in a messy and dangerous mix of crushed limestone, gravel and tar.