Thomas L. Farmer, a Washington lawyer who represented banking interests in his professional life and fought freeway construction through the nation’s capital as a civic activist, died Feb. 5 at his home in the District. He was 91.

The cause was progressive supranuclear palsy, a neurodegenerative disease, said a daughter, Sarah Farmer.

From 1970 to 2002, Mr. Farmer was general counsel to the Bankers Association for Foreign Trade, and for two years after that, he was senior counsel for international finance for the American Bankers Association.

He was chairman of the advisory board of the National Capital Transportation Agency from 1961 to 1964 and, about that time, he also helped form a citizens group called the Northwest Committee for Transportation Planning.

With the committee, he was a leader in a successful battle to block the construction of interstate highways through the city. Highway opponents argued that a network of interstate freeways would have torn up the city and destroyed neighborhoods.

Thomas L. Farmer in 1961. (Jim McNamara /The Washington Post)

Thomas Laurence Farmer was born July 26, 1923, in Berlin to an American father and a German Jewish mother. With his parents, he came to New York in 1933 at the time of Hitler’s rise to power.

He graduated from Harvard College in 1943, served in the Army during World War II, and then studied at the University of Oxford in England and in 1950 graduated from Harvard Law School.

In the early 1950s, he served as a covert operations officer with the Central Intelligence Agency. He then was a lawyer with the firm of Simpson, Thacher and Bartlett.

In 1962, he served as an attorney for the family of Frederic L. Pryor, an American graduate student imprisoned in East Germany. That year, Pryor was freed in the exchange for American U-2 spy-plane pilot Francis Gary Powers, who had been shot down over the Soviet Union.

Later he was general counsel to the Agency for International Development, and he was a partner in the firm of Kominers, Fort, Schlefer, Farmer and Boyer and the firm of Prather, Seeger, Doolittle and Farmer. He was a founder, director and general counsel of the Overseas Development Council, an independent policy research organization.

From 2005 to 2013, Mr. Farmer was with Consultants International Group, which serves European and Japanese companies.

His first marriage, to Elizabeth Becker, ended in divorce. Survivors include his wife of 12 years, Wanda Walton of Washington; three children from the first marriage, Daniel Farmer of Los Altos, Calif., Sarah Farmer of Irvine, Calif., and Elspeth Farmer of Palo, Alto, Calif.; and five grandchildren.