Becasue they had nothing better to do
I have experiences this in my own life when I join my schools reading Olympics team and we all had to learn an part of each book we were given because if one of us didn't have the answer we needed to be able to help each other out
Most liked the idea of joining the USA and of course did not resist. It is said that they accepted it with a fatality like which they accepted small pox,tuberculosis and hook worms. the worst that happened was dogs barking at US soldiers passing through.