Many people migrated from the north and east to the sun belt states during the 1950s because of

Many people migrated from the North and East to the Sun Belt states during the 1950s because of interstate highway system.

The development of the Inter State highway helped make transportation easier and facilitated the movement of both people and goods.

The Sunbelts comprissed states characterized by a warmer climate such as  California, Florida, Georgia, Texas, New Mexico etc.

In the 1950s and 1960s a large number of Americans moved to these areas from the North and North East of the country.

c) troops march forward in close formation against newer, more accurate weapons