1864—Congress authorized the phrase "In God We Trust" on American currency. It first appeared on the two-cent coin.
1876—The Boston Red Stockings defeated the Philadelphia Athletics 6-5 in the first National League Baseball game.
1898—The U.S. Navy begins a blockade of Cuban ports, and the USS Nashville captures a Spanish merchant ship—the first military actions in the Spanish-American War.
1970—Inaugural celebration of Earth Day, a national movement conceived by environmentalist and U.S. Sen. Gaylord Nelson, a Democrat from Wisconsin.
1993—The United States Holocaust Memorial Museum in Washington, D.C., is dedicated.