John Lansdale Jr., 91; Headed Manhattan Project Security

John Lansdale Jr., security chief for the Manhattan Project, which developed the first atomic bomb during World War II, has died. He was 91.

Lansdale died Friday of lung cancer at his farm home in Anne Arundel County.

Lansdale, who served in the Army during the war, also was instrumental in developing the Alsos Mission, which shortly before the war’s end investigated, located and removed the products of a German atomic bomb project.

As head of intelligence and security for the Manhattan Project, he was involved with the decision to appoint J. Robert Oppenheimer to lead the scientific team for the project at Los Alamos.

Lansdale defended his decision before Congress in 1954, when Oppenheimer’s security clearance was revoked.

“He was just 30 years old when he did this, and it still amazes me he did this important work at such a young age,” said his daughter, Sally Lansdale. “We’re very proud of him for his work there; he was very modest.”

Lansdale achieved the rank of colonel and was awarded the Legion of Merit and the Order of the British Empire.

Born in Oakland, Lansdale grew up in Houston and graduated from the Virginia Military Institute in 1933.

He received his law degree from Harvard University in 1936.

After graduation, he worked for the Squire, Sanders & Dempsey law firm in Cleveland.

After the war, Lansdale returned to the Cleveland law firm and worked there as a partner until his retirement in 1987.

During his 33 years in Cleveland, Lansdale served on the boards of various organizations, including the National Assn. of Anesthesiologists and the Cleveland Electric Illuminated Co.

He was on the City Council in Shaker Heights, Ohio, from 1949 to 1963.

Lansdale is survived by five daughters; 10 grandchildren; and 10 great-grandchildren.