James A. Williamson was a politician, and lawyer who served in the Union army during the American Civil War, rising to the rank of brigadier general. He received the Medal of Honor for his actions at the Battle of Chickasaw Bayou.
Williamson was born in Columbia, Kentucky in 1829. When he was fifteen years old his family moved to Iowa where he worked as a farmer, before studying law and being admitted to the bar. In the years prior to the Civil War he served as the chairman of the Iowa State Democratic Committee.
Source: Wikipedia