- 1707 Acts of Union comes into force, uniting England and Scotland to form the United Kingdom of Great Britain
- 1753 Publication of Species Plantarum by Linnaeus, and the formal start date of plant taxonomy adopted by the International Code of Botanical Nomenclature
- 1841 First emigrant wagon train leaves Independence, Missouri, for California
- 1886 US general strike for 8-hour working day begins
- 1931 Empire State Building opens in New York City
- 1883 Bob Rogers is acknowledged as the first American pro sports trainer when he is hired by the NY Athletic Club
Batman first appears in Detective Comics #27
On May 1, 1939
- 1576 Stefan Batory, the reigning Prince of Transylvania, marries Anna Jagiellon and they become the co-rulers of the Polish-Lithuanian Commonwealth.
- 1840 Women's rights activist Elizabeth Cady Stanton (24) weds fellow abolitionist Henry Brewster Stanton (34)
- 1850 Soldier William Tecumseh Sherman (30) weds Eleanor Boyle Ewing in Washington, D.C.
- 1881 Physiologist Ivan Pavlov (32) weds Seraphima Karchevskaya
- 1884 "Poems of Passion" author Ella Wheeler Wilcox (33) weds Robert M. Wilcox in Milwaukee, Wisconsin