<span>Because Wilson found it increasingly difficult to maintain U.S. neutrality after Germany, despite its promises in the Arabic pledge and the Sussex pledge, initiated a program of unrestricted submarine warfare early in 1917 that threatened U.S. commercial shipping.
hope this helped :)
alisa202</span>
Here are some reasons: They were curious. They were just natural born explorers. They wanted to spread their religion.
They wanted to be independent from being in control of other nations.
Hope that helps.
=)
Answer:
north american free trade agreement NAFTA