Thaddeus Hyatt (1816-1901) was an American lawyer and one of the inventors of reinforced concrete. In the 1850s he was active in the abolitionist movement and started settlements in Kansas. He also became acquainted with John Brown and after his death in 1859 in Harpers Ferry initiated a support fund for his family. He was suspected to have been involved in the occupation of Harpers Ferry, but refused to testify and sat three months in prison in 1860 of the Capitol. This edition includes correspondence and other papers from 1856–57. Some correspondence relates to the John Brown incident and the subsequent investigation.