1. Anti-Slavery Leader:
- Throughout his congressional career, Sumner was unwavering in his opposition to slavery and was the most outspoken abolitionist in the US Senate.
2. Vocal Critic of Slave Power:
- He delivered scathing speeches on the Senate floor exposing the evils and oppression of the slave system. One instance of such was the "Crime Against Kansas" speech that led to an assault on him in 1856.
3. Senator for Massachusetts:
- While representing Massachusetts in the US Senate during the war, Sumner served as the Chairman of the "Joint Committee for the Conduct of the War" from 1861 to 1862.
4. Advocate for African American Equality:
- Along with other Republicans, Sumner was instrumental in advocating for the abolition of slavery during the war and ultimately the establishment of the Equal Protection Clause of the Fourteenth Amendment that guaranteed full citizenship rights for African Americans.
5. Emancipation Supporter:
- Sumner consistently urged President Abraham Lincoln to take stronger measures for emancipation and the ultimate goal of destroying slavery.
6. Reconstruction:
- Sumner emerged as an influential Republican voice on Reconstruction policies with strong views, which set off conflicts within the party.