"Radio" or "Wireless"
That the railroads connected towns to towns, overal connecting states to states, causing them to rely on each other.
because United states :Unites
It depends on what unites states you speak of.
50
No
Yes
16000 slaves were in the united states
United States is commonly used as a noun, but it can function as an adjective. For example: The Unites States Navy (describing which Navy) The United States border (specificing which border)
To work
mostly protestant
It is New England
Obama