The first three volumes contain journals of Strahan's travels in Scotland, with records of expenses along the way, for 1751, 1759, 1760, 1766, 1768, 1773, and 1777. Strahan and Benjamin Franklin were in Edinburgh at the same time in 1759. The fourth volume contains "The particulars of the estate of Wm Strahan as it stood on the first of January 1755," and also for 1759 and 1761, with some miscellaneous accounts.

This diary is an account of a voyage from Newport (R.I.) to London, with descriptions of Boston, Dover, Edinburgh, and London. There are also many references to Benjamin Franklin in the diary.