To illustrate the depth one can access in our collections, we have compiled relevant archival imagery to frame a diverse cultural, political and chronological retrospective of noteworthy anniversaries. Be sure to bookmark this section as the calendar is a work in progress and will continue to expand.
| September | Year | Anniversary | Event |
| 1 | 1807 | 201st | Aaron Burr acquitted on charges of treason for conspiring to create a new American republic. |
| 1 | 1862 | 146th | At Second Bull Run, Confederates Lee and Jackson triumph when Union Gen. Pope withdraws from Chantilly. |
| 1 | 1862 | 146th | Major General Philip Kearny, one of the most promising Union commanders, dies in battle at Chantilly, at age 48. |
| 1 | 1862 | 146th | Union Major General and politician Isaac Ingalls Stevens, one of the U.S. Army's most promising leaders, dies in battle at Chantilly. |
| 2 | 1837 | 171st | James H. Wilson, a major general only 5 years after graduating West Point and officer who managed to rout Nathan Forrest, born. |
| 2 | 1862 | 146th | An unhappy Lincoln restores McClellan to full command after John Pope's disastrous failure at Second Bull Run. |
| 2 | 1862 | 146th | Union Brigadier General Thornton Brodhead, lawyer and politician, dies at age 40, mortally wounded at 2nd Bull Run. |
| 3 | 1777 | 231st | The "Stars and Stripes" flag flies in battle for the first time, at Cooch's Bridge, Maryland, during the Revolutionary War. |
| 3 | 1937 | 71st | Orson Welles directs, produces and stars in "Les Miserables," based on the novel by Victor Hugo. |
| 3 | 1902 | 106th | Sarah Orne Jewett, popular 19th-century novelist, is thrown from a carriage in an accident that ends her writing career. |
| 4 | 1807 | 201st | Robert Fulton begins the first commercial steamboat service, charging $7 for a ticket from New York City to Albany. |
| 4 | 1862 | 146th | Robert E. Lee's Confederate Army begins the Antietam Campaign by invading the North at Maryland. |
| 4 | 1957 | 51st | Arkansas Gov. Orval Faubus sends federal troops to block 9 black students from entering Little Rock's Central High School. |
| 5 | 1842 | 166th | Jesse James, Confederate soldier, outlaw, and bank robber, is born. |
| 5 | 1877 | 131st | Crazy Horse, a Dakota chief, is killed while in jail, by a U.S. soldier. |
| 5 | 1882 | 126th | First Labor Day parade, called "The Grand Demonstration of Working Men," is held in New York City, with 10,000 workers. |
| 6 | 1757 | 251st | The Marquis de LaFayette, French statesman who helped Washington during the American Revolution, born today. |
| 6 | 1837 | 171st | Oberlin College, first U.S. college to accept both male and female students, opens in Oberlin, Ohio. |
| 6 | 1847 | 161st | Writer and naturalist Henry David Thoreau leaves Walden Pond and returns to the home of his mentor Ralph Waldo Emerson. |
| 7 | 1927 | 81st | The first use of a television is demonstrated in San Francisco by Philo Farnsworth. |
| 8 | 1847 | 161st | Led by Winfield Scott and William Worth, the U.S. triumphs at the Battle of Molino del Rey, during the Mexican War. |
| 9 | 1862 | 146th | Lee issues the daring Special Order 191, splitting his Confederate Army, and sends William Jackson to capture Harpers Ferry. |
| 10 | 1847 | 161st | Hawaii's first theater, The Thespian, a renovated adobe building, opens in Honolulu, with performances by local amateurs. |
| 10 | 1897 | 111st | Nineteen unarmed coal miners are killed when police open fire on strikers in the "Latimer Massacre," in Latimer, PA. |
| 10 | 1977 | 31st | The guillotine falls for the last time when convicted murderer Hamida Djandoubi is executed in France. |
| 11 | 1777 | 231st | Gen. George Washington is defeated by British Gen. William Howe at the Battle of Brandywine. |
| 11 | 1897 | 111st | Strike by 75,000 coal miners from PA, OH, and WV concludes after 10 weeks, winning 8-hour days and the end of company stores. |
| 12 | 1812 | 196th | The U.S. inventor and industrialist who built the first successful rotary print press is born, Richard March Hoe. |
| 12 | 1862 | 146th | During the Antietam Campaign, the battle for Harpers Ferry begins when William Jackson and 6 divisions converge on Harpers Ferry. |
| 13 | 1847 | 161st | U.S. Gen. Winfield Scott storms the Chapultepec fortress in Mexico, during the Mexican War. |
| 13 | 1862 | 146th | Union troops at Frederick, Maryland, find a copy of Lee's plan wrapped around a cigar pack. |
| 13 | 1862 | 146th | McClellan has a unique opportunity when he learns of Lee's plan to invade Maryland, but Halleck convinces him Lee has set a trap. |
| 13 | 1862 | 146th | Lee learns McClellan knows his plan and sends Longstreet to support Gen. Daniel Harvey Hill. |
| 14 | 1847 | 161st | Gen. Winfield Scott, Chief of the U.S. Army, takes control of Mexico City. |
| 14 | 1862 | 146th | At the Battles of South Mountain and Crampton's Gap, Maryland, Union troops overwhelm the Confederates. |
| 14 | 1862 | 146th | Confederate General Samuel Garland is mortally wounded at Fox's Gap, Maryland. |
| 15 | 1857 | 151st | William Howard Taft, 26th U.S. president and chief justice of the Supreme Court, is born. |
| 15 | 1862 | 146th | The Confederates capture Harpers Ferry, MD, when Halleck foolishly orders the Union Army to hold its position. |
| 15 | 1962 | 46th | The Soviet vessel "Poltava" travels to Cuba with Soviet missiles. |
| 16 | 1782 | 226th | President George Washington first uses the Great Seal of the United States on a document. |
| 16 | 1832 | 176th | Confederate Gen. George Washington Custis Lee, oldest son of Robert E. Lee and great grandson of George Washington, is born. |
| 16 | 1892 | 116th | The Fifth Annual Convention of the National Republican League is held at Buffalo, NY. |
| 17 | 1787 | 221st | The completed U.S. Constitution is signed by a majority of the Constitutional Convention delegates. |
| 17 | 1862 | 146th | The bloodiest day in U.S. military history, the Battle of Antietam, took the lives of more than 23,000 soldiers. |
| 17 | 1942 | 66th | British Prime Minister Winston Churchill meets with Soviet Premier Josef Stalin in Moscow, as Stalingrad is attacked by Germany. |
| 17 | 1957 | 51st | Jazz musician Louis Armstrong cancels his U.S. sponsored trip to Russia due to U.S. indifference to violence in Little Rock. |
| 18 | 1862 | 146th | Confederate generals Jackson and Longstreet convince Robert E. Lee to retreat from Antietam. |
| 18 | 1862 | 146th | George McClellan, his Union troops too crippled to renew an attack, allows Lee to retreat from Antietam. |
| 18 | 1947 | 61st | The Air Force becomes a separate branch of the military when the National Security Act is passed. |
| 19 | 1777 | 231st | Generals Lincoln and Arnold yield the field but inflict heavy casualties at the Battle of Freeman's Farm, the first Battle of Saratoga. |
| 19 | 1777 | 231st | The Continental Congress flees the U.S. capital, Philadelphia, as the British approach. |
| 19 | 1827 | 181st | Jim Bowie stabs a Louisiana banker with the famous knife invented by his brother, Rezin Bowie. |
| 19 | 1862 | 146th | At the Battle of Iuka, Grant, Rosecrans and Ord thwart Bragg, Price and Van Dorn, when Price strikes prematurely. |
| 20 | 1777 | 231st | The British conduct a surprise attack on colonists, known as the Paoli Massacre, during the Revolutionary War. |
| 20 | 1927 | 81st | New York Yankee player Babe Ruth hits his record-setting 60th home run of the season. |
| 20 | 1932 | 76th | Mohandas K. Gandhi begins a hunger strike to protest the treatment of untouchables in India. |
| 21 | 1832 | 176th | Walter Scott, Scottish novelist and poet who wrote "The Lady of the Lake," dies. |
| 21 | 1897 | 111st | The New York "Evening Sun" publishes a famous editorial entitled "Yes, Virginia, There is a Santa Claus." |
| 21 | 1922 | 86th | Pres. Warren Harding signs a joint resolution to establish a Jewish homeland in Palestine, approving the Balfour Declaration. |
| 22 | 1692 | 316th | At the close of the Salem Witchcraft Trials, Mary Towne is the last of eight people hanged for witchcraft. |
| 22 | 1817 | 191st | John Quincy Adams becomes Secretary of State under President Monroe. |
| 22 | 1862 | 146th | After the Antietam tragedy, Lincoln issues a preliminary Emancipation Proclamation, to free all slaves owned by Southerners. |
| 23 | 1642 | 366th | Harvard College holds its first commencement. |
| 23 | 1862 | 146th | Russian novelist Count Leo Tolstoy marries Sophie Andreyevna Behrs, who later copied "War and Peace" seven times for him. |
| 23 | 1952 | 56th | Richard Nixon, Republican vice presidential candidate, gives his "Checkers" speech, refuting charges of improper campaign finances. |
| 24 | 1742 | 266th | Faneuil Hall, built by John Smibert and funded by wealthy Peter Faneuil, opens in Boston. |
| 24 | 1827 | 181st | Henry W. Slocum, who made major general after one year in the Union Army, becoming the second youngest major general, born. |
| 24 | 1862 | 146th | The Confederate States of America's Congress adopts the Confederate seal. |
| 24 | 1957 | 51st | Pres. Eisenhower orders U.S. troops to desegregate Little Rock Schools, telling the nation "Mob rule cannot be allowed." |
| 25 | 1847 | 161st | Gen. Zachary Taylor's troops capture Monterey, Mexico, after four days of fighting. |
| 25 | 1867 | 141st | The first all-black university in America, Howard University in Washington, DC, is created by the U.S. Congress. |
| 25 | 1937 | 71st | German Chancellor Adolf Hitler holds a meeting with Italian Premier Benito Mussolini in Munich. |
| 25 | 1957 | 51st | Nine black children are escorted to Little Rock Central High school by U.S. Army troops. |
| 26 | 1777 | 231st | Cornwallis's British troops occupy Philadelphia because Howe had recently defeated Washington and the capital was undefended. |
| 26 | 1937 | 71st | Great blues singer Bessie Smith dies needlessly after a car accident because emergency care is denied to African Americans. |
| 26 | 1972 | 36th | Emperor Hirohito meets with Richard Nixon in Alaska, at the first meeting of a Japanese monarch with a U.S. president. |
| 27 | 1722 | 286th | Samuel Adams, American revolutionary, politician, and brewer, is born. |
| 27 | 1871 | 137th | Former Confederate General James Clanton, who fought in the U.S. Army during the Mexican War, is killed. |
| 27 | 1927 | 81st | Franklin Roosevelt arrives in Warm Springs, Georgia, for warm water treatment of his polio in the town that became his second home. |
| 28 | 1787 | 221st | Congress orders that copies of the U.S. Constitution be submitted to each state for ratification |
| 28 | 1912 | 96th | Musician William Christopher Handy publishes the first blues song, his "Memphis Blues," introducing his 12-bar blues to America. |
| 28 | 1932 | 76th | With Babe Ruth pitching, the New York Yankees win the World Series by beating the Red Sox. |
| 29 | 1547 | 461st | Miguel de Cervantes, Spanish writer and author of "Don Quixote," novel of the Man of La Mancha, born. |
| 29 | 1867 | 141st | Sterling Price, Confederate general and Missouri governor, dies after a self-imposed exile in Mexico. |
| 29 | 1902 | 106th | David Belasco, actor and silent film writer, director and producer, opens the first Belasco Theater, near Times Square in New York. |
| 30 | 1827 | 181st | Ellis H. Roberts, U.S. journalist, politician, cabinet member and financier, born. |
| 30 | 1927 | 81st | Babe Ruth hits his 60th home run of the season, a major league record until 1961. |
| 30 | 1942 | 66th | Admiral Nimitz's B-17 plane gets lost on way to Guadalcanal and the crew uses a "National Geographic" map to find the island. |
| 30 | 1962 | 46th | Cesar Chavez, Mexican-American labor leader, founds the United Farm Workers. |
| 30 | 1997 | 11st | The Catholic Church in France apologizes for its silence when Jews were deported under Vichy's pro-Nazi regime. |