The term '1930s Dust Bowler' refers to a person who was part of the Great Plains migration during the 1930s. This migration, also known as the 'Okie' movement, was caused by the severe drought and dust storms that plagued the Great Plains region during this time. The term 'Okie' is derived from the name of the state of Oklahoma, which was one of the states most affected by the drought and dust storms.