Carry laws vary from state to state and specifics are determined by each state.
As regards your right to carry a weapon when you are off-duty, I can guarantee you that you it will not do you any good when you appear before the judge and say "Well, someone on Yahoo Answers told me that I could."...
Read "A Tree Grows In Brooklyn." It is set in Brooklyn around 1912 and goes forward.
Toni Morrison's "Jazz" is set in Harlem in the twenties.
Check out "The Great Gatsby." It is set in the twenties as well.
Call the lender and ask for the information. Very easy. You can get copies of all the paperwork. You can also get interest calculations for any period.