Reconstruction plans refer to the efforts taken by the Union to reunite and rebuild the United States after the Civil War. These plans included the Thirteenth, Fourteenth and Fifteenth Amendments to the Constitution, the Freedman's Bureau and the Military Reconstruction Acts of 1867. The first and second Industrial Revolution refer to the changes in the economic and manufacturing systems that occurred in the United States during the 19th and early 20th centuries. The first Industrial Revolution saw the introduction of new technology, such as the steam engine, and the shift from manual labor to machine labor. The second Industrial Revolution saw the introduction of new technologies, such as electricity and the assembly line, and the further mechanization of labor. The main difference between Reconstruction plans and the first and second Industrial Revolution is that the former was focused on reuniting the country and rebuilding its infrastructure, while the latter focused on technological and economic developments.