In 1856, Van Horn purchased the newspaper The Enterprise and renamed it The Kansas City Journal,[2] which published daily from 1858 until its closing in 1942.

[1] In 1861, Van Horn was elected to his first one year term as the 6th Mayor of Kansas City, the first Republican to hold the title.

[1] During the American Civil War, Van Horn enlisted in the Union Army and served as a lieutenant colonel of the Twenty-fifth Regiment, Missouri Volunteer Infantry.

[1] Van Horn was elected to represent Missouri's 8th congressional district in the Forty-seventh Congress from 1881 to 1883.

He then successfully contested the election of John C. Tarsney for representative of Missouri's 5th congressional district in the Fifty-fourth Congress and served from 1896 to 1897.