U.S. citizenship

Einstein became an American citizen in 1940. Not long after settling into his career at Princeton, he expressed his appreciation of the "meritocracy" in American culture when compared to Europe. According to Isaacson, he recognized the "right of individuals to say and think what they pleased", without social barriers, and as result, the individual was "encouraged" to be more creative, a trait he valued from his own early education. Einstein writes:

What makes the new arrival devoted to this country is the democratic trait among the people. No one humbles himself before another person or class. . . American youth has the good fortune not to have its outlook troubled by outworn traditions.^[55]:432

As a member of the National Association for the Advancement of Colored People (NAACP) at Princeton who campaigned for the civil rights of African Americans, Einstein corresponded with civil rights activist W. E. B. Du Bois, and in 1946 Einstein called racism America's "worst disease".^[70] He later stated, "Race prejudice has unfortunately become an American tradition which is uncritically handed down from one generation to the next. The only remedies are enlightenment and education".^[71]