- August 18, 0293 “BC – The oldest known Roman temple to Venus was founded, starting the institution of Vinalia Rustica.”
- August 18, 1201 The city of Riga is founded.
- August 18, 1227 Genghis Khan Dies
- August 18, 1541 “A Portuguese ship drifts ashore in the ancient Japanese province of Higo (modern day Kumamoto Prefecture). (Traditional Japanese date: July 27, 1541)”
- August 18, 1572 “Wedding in Paris of the Huguenot King Henry IV of Navarre with Marguerite de Valois, in a supposed attempt to reconcile Protestants and Catholics.”
- August 18, 1587 First English child born in the New World (Virginia Dare)
- August 18, 1587 “Virginia Dare, granddaughter of Gov. John White of the Colony of Roanoke, becomes the first English child born in the Americas.”
- August 18, 1590 “John White, the governor of the Colony of Roanoke, returns from a supply-trip to England and finds his settlement deserted.”
- August 18, 1634 “Urbain Grandier, accused and convicted of sorcery, burned alive in Loudun, France.”
- August 18, 1636 “The Covenant of the Town of Dedham, Massachusetts was first signed.”
- August 18, 1686 Cassini reports seeing a satellite orbiting Venus
- August 18, 1775 “The Spanish established a presidio (fort) and the town came to be called Tucson, Arizona.”
- August 18, 1817 “Gloucester, Mass, newspapers tells of wild sea serpent seen offshore”
- August 18, 1834 Mt Vesuvius erupts
- August 18, 1835 Last Pottawatomie Indians leave Chicago
- August 18, 1838 First US marine expedition
- August 18, 1838 “The Wilkes Expedition, which would explore the Puget Sound and Antarctica, weighs anchor at Hampton Roads in 1838”
- August 18, 1846 “Gen Stephen W Kearney’s US forces captures Santa Fe, NM”
- August 18, 1848 Camila O’Gorman and Ladislao Gutierrez executed on orders by Argentine dictator Juan Manuel de Rosas.
- August 18, 1864 Petersburg Campaign-Battle of Weldon Railroad day 1 of 3 days
- August 18, 1868 French astronomer Pierre Jules Csar Janssen discovers helium.
- August 18, 1868 Pierre Janssan discovers helium in solar spectrum during eclipse
- August 18, 1873 “The first ascent of Mount Whitney, Calif (14,494′)”
- August 18, 1894 Congress creates Bureau of Immigration
- August 18, 1903 “German engineer Karl Jatho allegedly flies his self-made, motored gliding airplane four months before the first flight of the Wright Brothers.”
- August 18, 1904 Chris Watson resigns as Prime Minister of Australia and is succeeded by George Reid.
- August 18, 1909 “Tokyo mayor Yukio Ozaki presents Washington, D.C. with 2,000 cherry trees, which President Taft decides to plant near the Potomac River.”
- August 18, 1914 Pres Wilson issues Proclamation of Neutrality
- August 18, 1917 “A Great Fire in Thessaloniki, Greece destroys 32% of the city leaving 70,000 individuals homeless.”
- August 18, 1917 “Capt. (acting Major) Okill Massey Learmonth (2nd Cdn. Infantry Batt.) wins the Victoria Cross at Hill 70, France”
- August 18, 1917 “Sgt. Fredrick Hobson (20th Cdn. infanctry Batt.) wins the Victoria Cross at Hill 70, France”
- August 18, 1920 “Nineteenth Amendment to the United States Constitution ratified, guaranteeing women’s suffrage.”
- August 18, 1920 “Tennessee ratifies 19th Amendment, guarantees women voting right”
- August 18, 1930 Eastern Airlines begins passenger service
- August 18, 1936 106.5? F-Hottest afternoon ever in Iowa to date
- August 18, 1937 Toyota Motor Company founded
- August 18, 1938 FDR dedicates Thousand Islands Bridge connecting US and Canada
- August 18, 1938 “The Thousand Islands Bridge, connecting New York State, United States with Ontario, Canada over the St. Lawrence River, is dedicated by U.S. President Franklin D. Roosevelt.”
- August 18, 1940 Chrysler founder Walter P. Chrysler dies