Which of the authors of the federalist papers wrote about foreign-policy

The author was Publius. Otherwise known as a pen name for Alexander Hamilton, James Madison and John Jay. Out of 85 articles, 51 were actually written by Hamilton, 36 by Madison and 5 by Jay. The others were combined by Madison and Hamilton.

Not sure, but John Jay wrote five, Madison wrote 25, and Hamilton wrote the other 51. It would most likely be Hamilton.