In the 1890s, Wilbur H. Siebert sent out questionnaires that proved invaluable for an early history of this institution that eventually credited over 3,000 people, mostly men, as being part of it. A Cincinnati museum named for this institution (10[1])opened in 2004 and is designed around a small, log-cabin-like structure recovered from Mason County, Kentucky. (10[1])Records kept by Sydney Howard Gay were publicized in a 2015 book on the “hidden history” (10[1])of this (-5[1])institution (10[1])by Eric Foner. (10[2])William Still wrote a history of this institution that drew on his time at the Philadelphia Vigilance Committee. (10[1]-5[1])Levi Coffin was sometimes called the (10[1])“president” of this institution and was one (10[1])of the numerous Quakers involved (10[1])in it. (10[1]-5[1])This institution’s so-called “reverse” version (10[1])facilitated (10[1])the kidnapping (10[1])of Solomon Northrup. (10[1])For (10[1])10 (10[1])points, name this informal, (-5[1])clandestine (10[1])network that helped escaped slaves reach freedom. (10[1])■END■ (10[2])