Andrew W. Mellon was influential in American financial practices for nearly six decades. Mellon was born on March 24, 1855, in Pittsburgh, Pennsylvania, the fourth son and sixth of eight children of Thomas and Sarah Jane (Negley) Mellon. When Andrew was four, his father was elected judge of Allegheny County, a post he held for the next ten years. In 1869, Thomas Mellon turned to finance, establishing the T. Mellon & Sons banking firm. Andrew studied in college for four years, but he left three months before graduating to start a lumber and building business. He was so financially astute in this venture and others that in 1882 he became the owner and manager of T. Mellon & Sons.

At that time, Pittsburgh was a significant part of the industrial boom in America, and Mellon helped establish the important role of banks in supplying capital for expanding industries. One such...