Louisa Ann Swain of Laramie, Wyoming becomes the first woman in the United States to cast a vote legally after 1807.

Louisa Ann Swain was the first woman in the United States to vote in a general election after the repeal of women's suffrage in New Jersey in 1807. She cast her ballot on September 6, 1870, in Laramie, Wyoming.

Laramie is a city in and the county seat of Albany County, Wyoming, United States, known for its high elevation at 7,200 feet (2,200 m), for its railroad history, and as the home of the University of Wyoming. The population was 31,407 at the 2020 census, making it the fourth-most populous city in Wyoming. Located on the Laramie River in southeastern Wyoming, the city is west of Cheyenne and 25 miles (40 km) north of the Colorado state line, at the junction of Interstate 80 and U.S. Route 287.

1807 (MDCCCVII) was a common year starting on Thursday of the Gregorian calendar and a common year starting on Tuesday of the Julian calendar, the 1807th year of the Common Era (CE) and Anno Domini (AD) designations, the 807th year of the 2nd millennium, the 7th year of the 19th century, and the 8th year of the 1800s decade. As of the start of 1807, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.