1To Benjamin Franklin from Samuel Cooper, 21 November 1778 (Franklin Papers)
ALS : American Philosophical Society I have just wrote to you by Mr Duncan Ingraham Junr. upon...
2To Benjamin Franklin from Samuel Cooper: Two Letters, 4 January 1778 [i.e., 1779] (Franklin Papers)
(I) ALS : American Philosophical Society; (II) ALS : American Philosophical Society; extract:...