1Thomas Jefferson to John Vaughan, 12 March 1820 (Jefferson Papers)
Two days after mine of the 8 th your’s of the 3 d came to hand. that will have informed you of every thing relative to D r Cooper , and particularly that we should be ready to pay him the 1500.D. the 1 st of May , the I herein committed a mistake, for I should have said 750.D. in his letter of Oct. 25. 19.