The Civil War significantly expanded the power of the federal government.

To preserve the Union and conduct the war, the federal government assumed greater authority over various aspects of life, including taxation, conscription, and civil liberties. The war led to the establishment of new agencies and policies aimed at supporting soldiers and managing war efforts. Additionally, the passage of constitutional amendments, such as the 13th, 14th, and 15th Amendments, further solidified federal authority in matters of civil rights and liberties, fundamentally reshaping the relationship between the states and the federal government.