I believe there is some confusion here. The townhouse in the McGee addition that housed the Confederate Women's Prison originally belonged to the family of Bingham's second wife, Eliza Thomas Bingham (1829-1876). George Caleb Bingham and Mattie Lykins did not marry until 18 Jun 1878.
Eliza's father, Rev. Dr. Robert Stewart, was the first president of William Jewell College in Liberty, Missouri. When the college ran out of money to pay faculty in 1856 - one explanation was that the border wars disrupted the economy - the Thomas family moved to Kansas City where Dr. Thomas founded the First Baptist Church. Among its first members were a former Baptist missionary, Dr. Johnston Lykins, and his second wife, Matilda Livingston. When Dr. Thomas died in 1859, the Binghams returned from Dusseldorf, Germany, then one of the art centers of the world. The Bingham family moved into the townhouse with Dr. Thomas's widow Elvira and Eliza's younger siblings. The artist had a third floor built as his studio. Elvira should have owned the townhouse, but due to the status of women at the time, her son-in-law was probably in control. (The exact information is available, but I do not have it at my fingertips. ) In late January, 1862, the Binghams, including infant son James Rollins, born 21 Sep 1961, and the Thomases moved to Jefferson City, Missouri, so Bingham could fulfill his responsibilities as State Treasurer. He had tried to decline the appointment, but the governor insisted he needed someone he could trust in the position. While the Thomas/Bingham home was vacant, General Ewing confiscated it. Union barracks were in the townhouses next door. The Thomas/Bingham home was a logical place for the women's prison. The added weight of the studio helped contribute to the disastrous collapse.
To address George Caleb Bingham's political role, two books stand out: for an art historical perspective, Nancy Rash's The Art and Politics of George Caleb Bingham; from an historical perspective, Paul Nagel's George Caleb Bingham: Missouri's Famed Artist and Forgotten Politician.