Question

George Washington tried but failed to convince Americans to avoid

getting involved with political parties
isolating the nation from international relations
setting term limits for the president
using slaves in farms and in factories

Answer 1

Getting involved with political parties. This is because he felt it would divide the country, but in the end he couldn't prevent the formation of the parties themselves. 

Answer 2

George Washington tried but failed to convince Americans to avoid getting involved with political parties.