I have a problem with America

He doesn't stop sending in missionaries, and after I wiped out Indonesia he denounced me 2 times in a row. I'm scared to attack him because he's pretty far away and his land is massive but i'm kind of scared he will attack me. I have a plan to wait till I get good ships in the modern era since all of his big cities (Washington and Boston) are on the water. Should I wait till the era? I'm number 1 in everything except goods (2) and approval because of my 'warmongering'.

Wait for Battleships (three tiles range, four if you got the range promotion), and possibly aircraft carreers full of bombers. Bring few destroyers to size his city and protect from his B-17

Get inqusators in your cities, that will keep him from converting them.
Even better convert all of his cities and he will not be able to get a missionary from his religion, only from your religion

PS that will hurt your relationship with him.

Unless he's beating you in points, I wouldn't worry to much. If he is, look for some deserted land for you to get your troops to. Then advance on him.

Thanks for the tips