The Civil War (1861-1865). Modern historians call the Civil War the "first modern war" in American history. During this time, factories in the North produced guns and supplies for the war effort; railroads crisscrossed the country moving supplies and armies; generals used the telegraph to communicate over large distances; and a new ironclad navy driven by steam power blockaded the south. The scope of the struggle increased the power of industry and government in the North and led to the destruction of large areas of the South as the armies marched back and forth.

In 1863, President Abraham Lincoln pledged "a new birth of freedom" in his now-famous Gettysburg Address. For African Americans this would mean freedom from slavery. With the passage of the 14th and 15th amendments to the Constitution, African Americans were guaranteed their civil rights on an equal basis with white Americans. Thomas Jefferson's words stated in the Declaration of Independence in 1776 "that all men are created equal" now had meaning for millions of Americans that had been excluded from the social compact.