He represented several high-profile clients, including President Warren G. Harding, oil tycoon Edward L. Doheny, and banker Andrew Mellon.

Hogan grew up in a household run by two widowed women, along with his cousin James F. Byrnes, who went on to become governor of South Carolina.

His most notable case was his defense of oil tycoon Edward L. Doheny and the Pan-American Petroleum and Transport Company in a series of trials from 1924 to 1930.

The company was forced to cancel its lease, but Hogan succeeded in clearing Doheny on charges of bribery and conspiracy to defraud the government.

In 1935 he successfully defended Andrew Mellon on charges of tax evasion against assistant attorney general, Robert H.

[2] Other clients included former president Warren Harding, the General Electric Company, Armour & Co., and Swift & Co.[3] He appeared on the cover of Time magazine in 1935.

Among other things, it filed an amicus brief in Hague v. Committee for Industrial Organization, an important case on freedom of assembly.

[6] Hogan also supported the conservative Walter-Logan bill, which was passed by Congress and would have imposed strict constraints on federal administrative agencies if it had not been vetoed by Franklin Roosevelt.

[8] On December 11, 1938, under the auspices of the General Jewish Council, Hogan denounced racial and religious intolerance in a half-hour speech aimed at fellow Catholics.

Titled "An American Catholic Speaks on Intolerance", Hogan's speech was interpreted as a rebuke of Charles Coughlin, an antisemitic priest whose weekly radio broadcasts were attracting millions of listeners across the country.

Where they are the equals of all other citizens, as in America, democracy lives and flourishes, and all men are free whatever their faith.The speech was widely quoted in newspapers the next day.

In addition to his professional work, Hogan served for a time as vice president of the Shakespeare Association of America.