Noah Webster recognized the new sense in his dictionary of 1828. There is nothing new transpired since I wrote you last - Abigail Adams Sense 1 appears to have developed in the late 18th century it was well enough known to have been used by Abigail Adams in a letter to her husband in 1775.
Sense 1 of transpire is the frequent whipping boy of those who suppose sense 2 to be the only meaning of the word. Can transpire mean 'to occur'?: Usage Guide
