Who invented the ferry boat like the type used to cross rivers and
such on the Oregon Trail during the time when all the settlers were
heading west?  I think it was during the 1800's.  They would put their
wagons and oxen, horses, etc. on top and cross the rivers, etc. 
Thanks!

If you are referring to the floating barge that was pulled across with
a primitive system of ropes, this was probably an ancient
unattributable invention of necessity that dates (just a guess) to the
Egyptian or Viking era or some similar ancient water navigating
tribes.

Regards;
tutuzdad-ga

This might be of interest:

"In 1811, the first steam-powered ferryboat, the Juliana, was put into
operation by inventor John Stevens between New York City and Hoboken,
NJ. Stevens designed improvements in steamboats, obtained one of the
first U.S. patents (1791) and experimented on the Passaic River, (1798
- 1800), with the steamboat, Polacca, but unsuccessfully due to
excessive vibrations and leaks. By 1803, Stevens had patented an
improved multitubular boiler and outfitted the Little Juliana which
sailed successfully in New York harbor (1804) and thus was one of the
earliest twin screw sailboats. He built other ships. Then, in 1811, he
purchased a commercial ferry license in NY state and operated a horse
powered ferry while building the first steam ferry, Juliana."

http://www.todayinsci.com/10/10_11.htm