In 1910 the immigrants were primarily male, with about 131 men per 100 female immigrants. almost 6 percent of them that year were under the age of 15 while only 9 percent were over 65. About 87 percent of all immigrants entering the U.S. in 1910 came from Europe.
America's developing economy presented job opportunities for the foreigners, many of whom had hoped to later return to their native countries. Mining also lured large numbers of unskilled immigrants to Pennsylvania's large coalfields.