Which of the following crippling strikes ended successfully for the union during the many strikes that hit the u. s. during 1919?
a. united mine workers
b. boston police officers
c. united states steel
d. pullman car

The answer is letter A. United Mine Workers. United Mine Workers is a crippling strike that ended successfully for the union during the many strikes that hit the U.S. during 1919. It is a North American labor union representing coal miners.

The answer is d.  the north had organized schools, whereas the south had few organized schools.