One of Einstein's most enduring legacies among physicists is his theory of gravity, known as "general relativity." Einstein's beautiful theory, completed in 1915, was born in a time of war, which shaped how other physicists and astronomers came to learn about and evaluate his work. Over the course of the twentieth century, the fortunes of general relativity continued to be shaped by worldly matters: first by his Nazi detractors, later by a new generation of American physicists immersed in the Cold War.