Look in your average American history book, and any reference you find to William Henry Seward will probably be because a) he negotiated the purchase of Alaska from Russia, and/or b) he was the Secretary of State under President Lincoln.
Few of those books would focus on Seward's abolitionists beliefs.
(For the record, I am not related to William Seward. Seward is my married name. My husband's grandfather Seward came from England in the early 1900's.)
William Henry Seward was born in Florida, New York, on May 16, 1801. His father, Samuel, was the town postmaster, and he was a slaveowner. At the time, slavery was legal in New York State; it was abolished in 1827. Seward went to school with the children of his father's slaves and later, he said he preferred the atmosphere of the slave kitchen to that of his father's parlor. Later, he wrote in his autobiography, "I early came to the conclusion that something was wrong with slavery and that determined me to be an abolitionist."
In 1820, he graduated from Union College. Two years later, he was admitted to the bar. After moving to Auburn, New York, he became a junior partner to Judge Elijah Miller. Soon, he would also be Miller's son-in-law. He fell in love and married Miller's daughter Frances. They both believed that slavery was wrong, and that was the core belief that brought them together.
Seward supported the rights of African-Americans and, throughout his career, stayed opposed to slavery. He called for a gradual ending of slavery throughout the United States; his wife, however, wanted immediate abolition and emancipation of all slaves. Both Sewards used their wealth to support the abolition movement, and they also financially supported Frederick Douglass' North Star newspaper, based in Rochester.
He served two terms as governor of New York, between 1839 and 1843, and it was during that time that he gained a national reputation as an outspoken abolitionist. When southern states asked for fugitive slaves to be returned, Seward refused.
Seward was elected to the Senate in 1849, and his repeated statements that slavery was morally wrong angered Southerners. While he acknowledged that, under the Constitution, slavery was legal, he denied that the Constitution recognized or protected slavery. In 1850, he remarked that "there is a higher law than the Constitution".
During the 1850's, the Sewards used their house at Auburn, New York as a safe house for runaway slaves. It was a deliberate act of civil disobedience. They used two rooms in the house as hiding places.
In 1859, the Sewards helped Harriet Tubman, who led hundreds of slaves to freedom, buy seven acres of land on their property. There, Tubman built a home where she lived until she died.
Seward's role as President Lincoln's Secretary of State is much better known. Seward didn't like Lincoln very much at first, but as they continued to work together, Seward came to respect Lincoln and was known as Lincoln's right-hand man. They became close friends because of their collaboration. He worked with Lincoln on the Emancipation Proclamation, and negotiated an 1862 treaty, the Lyons-Seward Treaty, which outlined measures by which the United States and Great Britian would end the Atlantic slave trade.
Abraham Lincoln was not the only one attacked on April 15, 1865. Lewis Powell, a confederate of John Wilkes Booth, was assigned to attack Seward as part of a plot that included killing Lincoln. Powell stabbed Seward, who was confined to bed due to a carriage accident, several times in the face and neck. Seward carried the scars for the rest of his life.
Seward would go on to serve as Secretary of State under President Andrew Johnson. He died on October 10, 1872. Thus ended the life of a man whose moral opposition to slavery helped end its practice.
McLean, Maggie, "Frances Seward", Civil War Women
"William Henry Seward", Seward House Historic Museum