Yes, although the legality of "freeing" slaves in the South between c. 1831 - 1865 was complicated, and in some cases outright forbidden. One name I did not see mentioned in the other thread that I often mention in my courses is Elizabeth Van Lew, a Richmond socialite and Quaker who, along with her brother, sought to reunite families who had been split up through sale. Specifically, they would attend slave auctions in Richmond with the intent of purchasing families to prevent their separation by sale, and then giving them a "free" life on the Van Lew estate. There is some disagreement about whether or not the Van Lews were participants in the Underground Railroad prior to the war, but during the Civil War, she did facilitate the escape of enslaved people and Union soldiers from areas like Libby Prison using a series of safehouses that had been set up to get them North.
Because freeing slaves was [edit] actually illegal impractical to the point of near-impossibility [end edit] under Virginia law, she issued informal papers of manumission to enslaved people "belonging" to her family, and arranged for them to conduct their own affairs and control their own finances in Richmond. One of these individuals, Mary Jane Richards (aka "Mary Bowser") became one of the most useful Union spies during the war, even infiltrating Jefferson Davis' residence while disguised as a laundress. Van Lew ran probably the most successful intelligence operations during the war, providing consistently useful and occasionally crucial information to General Grant and others, to the point that Grant appointed her postmaster of Richmond after the city fell. She disdained the term "spy," but there is no doubt she would have been in grave danger of being hanged as such if she had been discovered by the Confederate government.
Additional sources:
You may want to refer to a previous thread located here:
https://www.reddit.com/r/AskHistorians/comments/35ij72/did_people_ever_buy_slaves_to_set_them_free