The Texan towns were tiny.

The whole fringe of Texan settlements was small.
The Texans were but fifty or sixty thousands against the seven or eight millions of Mexico, and now that they knew a great Mexican army was in Texas the scattered borderers would be hard put to it to defend themselves.

He did not believe that in any event they could gather a force great enough to cut its way through the coil of Santa Anna's multitude.
But Travis' faith in Bonham, at least, was justified.

The next night, about halfway between midnight and morning, in the darkest hour, a man scaled the wall and dropped inside the plaza.

It proved to be Bonham himself, pale, worn, covered with mud and dust, but bringing glad tidings.