Sam Houston was trying to make it to La, where President Jackson had stationed a large contingent of US troops. Houston then planned to annihilate Mexican forces with the aid of US troops. The US was solidly on the side of the Texans.
you must have went to PUBLIC FOOL SCHOOL.
Read this article
http://en.wikipedia.org/wiki/First_Texas_Navy
Here you will find the details about the US navy ship seized by Texicans for running guns to Mexico to fight against Texians.