Immigrant and ethnic themes were the basis for much of the humor of the early 20th century, a period of great emigration from Europe. Many of the first comic-strip cartoonists were themselves immigrants of first-generation Americans. Opper, for example, was the son of an Austrian immigrant. Bringing Up Father, by George McManus (1884-1954), chronicled the life of an Irish immigrant worker who had made good and his social-climbing wife. Harry Hershfield (1885-1974) created his classic strip Abie the Agent in 1914, in which he depicted the milieu of a Jewish middle-class businessman; it has been called the first truly adult comic strip in America.