1821 - Missouri became the 24th state to join the Union.
1846 - The Smithsonian Institution was chartered by the U.S. Congress. The "Nation's Attic" was made possible by $500,000 given by scientist Joseph Smithson.
1856 - In Louisiana, a hurricane came ashore and killed about 400 people.
1859 - In Boston, MA, the first milk inspectors were appointed.
1869 - The motion picture projector was patented by O.B. Brown.
1881 - Thomas Edison's exhibit opened the Paris Electrical Exhibition.
1885 - The first electric streetcar, to be used commercially, was operated in Baltimore, MD, by Leo Daft.
1921 - Franklin D. Roosevelt was stricken with polio.
1927 - Mount Rushmore was formally dedicated. The individual faces of the presidents were dedicated later.
1949 - In the U.S., the National Military Establishment had its name changed to the Department of Defense.
1973 - Arnold Palmer did not make the cut for the final two rounds of the PGA Golf Championship. It was the first time in his career.
1977 - The "Son of Sam," David Berkowitz, was arrested in Yonkers, NY. Berkowitz, a postal employee, had shot and killed six people and wounded seven others.
1981 - Pete Rose hit a single and broke the National League all-time hit record with his 3,630 hit.
1994 - U.S. President Clinton claimed presidential immunity when he asked a federal judge to dismiss, at least for the time being, a sexual harassment lawsuit filed by Paula Corbin Jones.
1995 - Timothy McVeigh and Terry Nichols were charged with 11 counts in the Oklahoma City bombing.
1995 - Michael Fortier pled guilty in a plea-bargain agreement. The agreement required that he testify for the prosecution in the Oklahoma City Federal building bombing trial.