A central figure in Illinois' early history, Sidney Breese forged an eventful public life that spanned the state's transition from a frontier territory to a modern industrial society. Joseph A. Ranney tells the story of the lasting achievements and far-reaching legal decisions that defined Breese's career. Born in New York, Breese moved to Illinois in 1818. An ambitious personality combined with acumen in law, politics, and business boosted Breese into the state's frontier elite and involved him in the political controversies that roiled the Jacksonian Era. First a circuit court judge, Breese rose to the state Supreme Court before his election to the US Senate in 1842. Breese focused his senatorial energies on westward expansion and transforming the nation into a world power - ambitions symbolized by his pivotal role in the creation of the Illinois Central Railroad. After returning to the state Supreme Court, Breese ruled on essential cases that enshrined expansionist jurisprudence in American law and regulated the growing power of corporations in post-Civil War America. A first full-length biography, Sidney Breese places the life of an overlooked figure within legal and Illinois history.