With which american institution were frederick douglass, levi coffin, and harriet tubman most closely associated?
a first industrial revolution
b underground railroad
c development of the canal system
d creation of institutions of higher education

The main reason the us senate rejected the treaty of versailles was because, isolationists felt the us should not have gotten into the war. republicans had gained power in the senate. democrats had gained power in the senate. european nations wanted to punish germany.