What 2 inventions westward expansión?

Amusing that it's "expansion" two inventions would be the train and steamboat. both provided a source of transportation. Hope that helps.
-Tralynn
 

 Peter Cooper, a mechanic that taught himself, built a steam locomotive to pull the train cars or carriages.  His steam engine could travel 18 miles per hour.  This was three times faster than the horse-drawn trains that Americans were using.  Making a railroad was cheaper than digging canals and rails did not freeze in the winter.  The railroad era in America began and people and goods were now moving across the country faster than ever.

Idon’t know ask your teach u little cheater