There are 50 sates in the united states of america
because United states :Unites
It depends on what unites states you speak of.
Yes
No
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)
It is New England
To work
Obama
50
mostly protestant