Everett Seixas, Jr., came from one of the most historically significant Jewish families in the United States. One ancestor led the oldest synagogue in New York City during the American Revolution. Another received a famous letter from George Washington, who assured him that the rights of Jews would be respected in the new American republic. One relative helped establish the New York Stock Exchange. Still another was the poet Emma Lazarus, whose ode to “the huddled masses yearning to breathe free” famously honored the Statue of Liberty. And then there was Mr. Seixas. Born in New York City in 1911,...