Although he briefly left that position to become a law partner to Judge Walter T. Stanton, he returned to the counsel's office during the administration of Mayor William Dever.

Though he was not interested in the position, probably because of ill health and the limits placed on the interim mayor's powers, Corr yielded to the entreaties of Democratic Party leader Patrick Nash, who wanted an interim appointee to serve until a permanent replacement could be selected.

[5] As Acting Mayor, Corr lacked the ability to sign tax warrants, limiting salary payments for city and school employees.

When five aldermen traveled to Hot Springs, Arkansas, Corr followed them to bring them back to Chicago to ensure that his replacement could be elected quickly.

[4] At the time of his death, Corr was serving as alderman and running uncontested for election as judge of the circuit court.