Republican State Senator from Monroe County, Michigan, 1850-1851, Michigan Supreme Court Justice, 1858-1875, U.S. Senator, 1875-1879, and U.S. Minister to Peru. Letters to his children, business letters from his law partner Robert M. McClelland, Catholic Bishop Peter P. LeFevre and Nathaniel L. Christiancy; legal documents, Civil War address, Michigan Supreme Court docket book, and miscellaneous papers.
The Isaac Peckham Christiancy collection relates primarily to the period in his career prior to becoming a United States Senator and Minister to Peru. The papers have been arranged into the following series: Background Information; Correspondence; Business, financial, and miscellaneous; Legal files: law practice and Michigan Supreme Court. Of note are letters to his children and business letters from his law partner Robert M. McClelland, Catholic Bishop Peter P. LeFevre and Nathaniel L. Christiancy. In addition, there is an address he gave during the Civil War.