How did the gypsy moth get here?

E.L. Trouvelot, who was interested in breeding a better silk worm, first brought the gypsy moth from France to Massachusetts in 1869. Some moths escaped to his neighborhood and quickly became established. Since their introduction, gypsy moths have spread north, south, and west, eating their way from Maine to North Carolina and into central Wisconsin. Despite state and local control efforts, the infestation continues to spread south and west and threatens to move into Minnesota.