Answer :

He ordered the use of police dogs and fire hoses against the marchers. 

The way T. Eugene Connor reacted to civil rights marchers in Birmingham, Alabama was by ordering the use of police dogs and fire hoses against the marchers.

Protests in Birmingham initiated with a boycott led by Shuttlesworth in order to pressure business leaders to open employment to people of all races, and end segregation in public facilities, restaurants, schools, and stores.

Theophilus Eugene Connor was an American politician who served as an elected Commissioner of Public Safety for the city of Birmingham, Alabama, for more than two decades.