The Ark in the movie was the Ark of the Covenant (the gilded gopher wood box built by Moses on the instructions of God); as such it contained the fragments of the original tablets of the Law, a jar...
USA PG/Canada 14A
the Second World War (the war between many nations that lasted from 1939 to 1945)
June 12, 1981.
The movie was released in on June 12, 1981. The movie itself takes place in 1936.