This paper traces the sources of the widely available standard figures for Jewish voting in American presidential elections, which have previously been only vaguely identified. The pre-polling results for 1916–1932 data turn out to be only for Manhattan, and do not take sufficient account of voting patterns in other cities and of voting for the Socialist Party. The standard figures for the 1936–1968 period do not generally correspond to national surveys taken for those elections. The figures starting in 1972 are based on one set of exit polls, but should instead combine all of the exit polls. The 1924, 1952, and 1984 data are given particular attention because the Jewish vote was thought to be realigning in those years. Revised estimates find large differences for 1924 and 1948 and provide a firmer basis for tracing trends in Jewish voting.