■ On July 4, 1776, the Declaration of Independence was adopted by delegates to the Second Continental Congress in Philadelphia. ■ In 1802, the United States Military Academy officially opened at West Point, N.Y. ■ In 1815, the cornerstone was laid for a monument in Baltimore honoring George Washington (the monument was completed in 1829). ■ In 1831, the fifth president of the United States, James Monroe, died in New York City at age 73. ■ In 1845, Henry David Thoreau began his two-year experiment in simpler living at Walden Pond, near Concord, Mass. read more