Freedom, Union, and Power analyzes the beliefs of the Republican Party during the Civil War, how those beliefs changed, and what those changes foreshadowed for the future. The party's pre-war ideology of "free soil, free labor, free men" changed with the Republican ascent to power in the White House. With Lincoln's election, Republicans faced something new-responsibility for the government. With responsibility came the need to wage a war for the survival of that government, the country, and the party. And with victory in the war came responsibility responsibility for saving the Union-by ending slavery-and for pursuing policies that fit into their belief in a strong, free Union.

Michael Green shows how Republicans had to wield federal power to stop a rebellion against freedom and union. Crucial to their use of federal power was their hope of keeping that power-the intersection of policy and politics.