William Johnson Copp (August 13, 1811 – December 15, 1889) was an American lawyer, Republican politician, and Wisconsin pioneer.
In Tennessee, Copp became involved in politics with the Whig Party, and was active in the 1844 United States presidential election on behalf of Henry Clay.
Shortly after the 1844 election, Copp moved to Aberdeen, Mississippi, where he was a junior law partner to his wife's brother, Matthew W.
The following year, rather than running for re-election, he ran for Wisconsin circuit court judge, but came in third in the election, behind Benjamin Allen and the victor, S. S. N.
He ran for office one final time in 1879, running as the Democratic nominee for Wisconsin State Assembly in the Pierce County district, but he came in a distant third behind the Republican incumbent Nils P. Haugen and a third party Greenbacker.
Daniel Copp was raised in Connecticut and was a farmer by upbringing, but after moving to Georgia he became involved in the shipping industry and owned one or two sailing vessels.
Daniel Copp may have been appointed mayor of St. Augustine, Florida, during Andrew Jackson's time as military governor of the territory.
William Copp was also a descendant, via his paternal grandmother, of the colonist George Denison, who came to the Massachusetts Bay Colony from England about 1640.
[12] Their younger son, Joseph Matthew Copp, served in Company A of the 12th Wisconsin Infantry Regiment through most of the American Civil War.
He also had a close connection with Copp's former partner, Orrin T. Maxson, who served as captain of his company through nearly his entire service in the war.