He spent the war in Paris, performing complex diplomatic negotiations with the French and, later, England, that kept the US from floundering before it got off the ground. Franklin was in his 70s while all this was going on.
I read Chapters 13-15 for Paris in July
My favorite part of his time in Paris, though, was shortly after the peace treaty was signed. Franklin was in France for Balloon Mania in 1783 when the first hot-air balloons were flown. He was present for the first manned flight on November 21, flown by brothers Joseph and Etienne Montgolfier.
As a huge crowd cheered and countless women fainted, the balloon took off with two champagne-toting noblemen, who initially found themselves snared by some tree branches. “I was then in great pain for the men, thinking them in danger of being thrown out or burnt,” Franklin reported. But soon they were free and gliding their way over the Seine, and after twenty minutes they landed on the other side and popped their corks in triumph. Franklin was among the distinguished scientists who signed the oficial certification of the historic flight the following evening, when the Montgolfiers called on him at Passy. (p. 420)
I love picturing Franklin, and the Seine, and the first manned hot-air balloon.