Charles Mason and Jeremiah Dixon began surveying the Mason-Dixon line.
The Continental Congress approved the Articles of Confederation, the precursor to the U.S. Constitution.
Explorer Zebulon Pike spotted the mountaintop now known as Pikes Peak.
The cornerstone of the Jefferson Memorial was laid by President Roosevelt.
About 250,000 protesters against the Vietnam War, the largest war protest ever, converged peacefully on Washington, DC.
Hu Jintao replaced Jiang Zemin as China's Communist Party leader.