Simplify the following text for a Grade 14 native English-speaking person.
Original: During and after the American Revolution , Jay was a minister ( ambassador ) to Spain and France , helping to fashion United States foreign policy , and to secure favorable peace terms from Great Britain ( with Jay 's Treaty of 1794 ) and the First French Republic .
Simplified: During and after the American Revolution , he was a minister ( ambassador ) to Spain and France , helping to fashion American foreign policy and to secure favorable peace terms from the British and French .