1To Thomas Jefferson from Isaac Briggs, 9 January 1807 (Jefferson Papers)
Washington City 9 of the 1 mo 1807
2From Isaac Briggs to James Wilkinson, 10 January 1807 (Jefferson Papers)
Washington City 10 of the 1 mo. 1807
3To Thomas Jefferson from Isaac Briggs, 20 October 1808 (Jefferson Papers)
Washington City 20 of the 10 mo 1808.