The answer to this question would be “Beringia”.
Today, Beringia<span> is the land and marine area bordered on the west
by the Lena River; on the east by the Mackenzie River; on the north by 72
degrees north latitude in the Chukchi Sea; and on the south by the tip of the
Kamchatka Peninsula.</span>
Generally speaking, "assembly line jobs" did not represent an obstacle during this time, since this in fact increased productivity through the "specialization of labor".
