This is in spite of the fact that little mechanization existed in the Postal Service prior to 1970 and large amounts were added in the 1970s.
The postal service used machinery way before the 70s
mnli hypothesis: The postal service used machinery way before the 70s premise: This is in spite of the fact that little mechanization existed in the Postal Service prior to 1970 and large amounts were added in the 1970s.