- Manuscript copy of a correspondence between Edmund Jackson and Hon. Robert C. Winthrop, in which Jackson asks for Winthrop's position on slavery before his election to United States Congress. Includes Winthrop's response dated November 2, 1840, in which he replies that he "cannot regard it as desirable or expedient to attempt any alteration of the Constitution in relation to slavery.", New-York Historical Society
- Resolution produced by the Commonwealth of Massachusetts that the United States Congress must abolish slavery in the District of Columbia. Includes note that the "resolves were passed by the House in the 21st, & by the Senate of the 23 March" and that the resolutions are the same as are referred to in the letters of E. Jackson and R. C. Winthrop., New-York Historical Society