[2] His paternal grandparents were James Watson Webb, the United States Ambassador to Brazil during Abraham Lincoln's administration, and Laura Virginia Cram.

[4] After graduating from Yale, Webb started his career with the Chicago and Northwest Railway before joining Marsh & McLennan, the New York insurance brokerage house in 1911.

[4] During World War I, Webb served in France as a captain of the 311th Field Artillery, 79th Infantry Division, which saw action during the Meuse-Argonne Offensive.

His wife drove an ambulance in New York City, and was named Assistant Director of the Motor Corps during the War,[10] and in 1942, during World War II she joined the Civilian Defense Volunteer Organization, and directed the Pershing Square Civil Defense Center and its blood bank.

[24][26] He was also a trustee of the New York Zoological Society and Norwich University in Northfield, Vermont, where he received an honorary Doctor of Laws in 1955.