The last wolf in New Hampshire was killed in 1887, in Connecticut and Rhode Island in 1742, in Massachusetts in 1743. Though EXTREMLY few still live in New Hampshire and Maine most left live in the few sanctuaries and conservation centers. Wolves control the prey levels and with an extremly high rate of White Tailed Deer, they could control that. If properly introduced and tagged to be tracked, possibly some spayed and neutered before release so the population does not grow too much, the rate of deer increase will be dropped. This would cause the lowering of accidents caused by deer on the roads.
Wolves are an important part of a healthy ecosystem. They also can lower the number of coyotes. While wolves do hunt small animals, the abundance of large will out weigh it in these areas.