At his death he left his widow, the former Elizabeth Lowe, four children, Catherine, Louise, David, and Anne, and ten grandchildren.

[2] Gamble first toured in 1908, accompanying his parents, then after graduating from Princeton in 1912, studied labor and industrial economics at University of California, Berkeley, spending six months on a fellowship working at a reform school for delinquent boys.

In 1926, Gamble traveled for three weeks in the Soviet Union with Sherwood Eddy, a longtime mentor.

As China became more and more inflamed by patriotic agitation and warlord fighting, he found hope in the Ting Hsien Experiment (Ding Xian Experiment) in Rural Reconstruction conducted by James Yen’s Mass Education Movement.

Jonathan Spence concludes of Gamble that his "findings were open-minded, clear headed, methodologically intelligent (though not always beyond criticism by scholars of different views), startlingly imaginative, and -- when presented in photographic form -- vigorous, ebullient, unsentimental, and starkly, yet never cruelly, illustrative of the deep and real suffering that lay at the heart of China's long revolution.