John Allen Campbell (October 8, 1835 – July 14, 1880) was a politician and officer in the U.S. Army. Campbell was the first Governor of the Wyoming Territory.
Campbell was born in Salem, Ohio, and attended public school in Ohio. In 1861, Campbell joined the Union Army in the Civil War. He served as a publicity writer and later as adjutant general on Major General John M. Schofield's staff. He advanced from lieutenant tobrevet brigadier general.
Campbell continued to serve under Major General Schofield during the Reconstruction Period, and in Virginia helped set up senatorial and representative districts. President Ulysses S. Grant appointed him Governor of Wyoming Territory in 1869 and again in 1873. While Governor, Campbell approved the first law in United States history explicitly granting women the right to vote. The law was approved on December 10, 1869. This day was later commemorated as Wyoming Day.
Campbell was appointed American Consul at Basel, Switzerland, on December 3,1877, and resigned on February 4, 1880
Campbell County, Wyoming, is named after him