Complex sentence: This was primarily because the voting age was lowered from 21 to 18 in 1971 with the 26th amendment, a lot of states started to lower their minimum drinking age in response most of it occurring in 1972 or 1973.
Split into simpler sentences: This was primarily because the voting age was lowered from 21 to 18 in 1971 with the 26th amendment. A lot of states started to lower their minimum drinking age in response, most of this occurring in 1972 or 1973.