This is a sexual act where 2 or more men have sex with a black woman at the same time. Many refer to 2 men having sex with a female at the same time as 'Running a Train,' hence the name since it pertains to the same act with a black female. The black woman who is part of the act can then be refered to thereafter as a 'Harriet Tubman'. (See Hariet Tubman). This act can be performed anywhere.
Billy: Yo last night me and Bobby had an underground railroad with that black girl Marissa.
Ralph: What do you mean?
Billy: We were chillin in my car & she started sucking my dick when Bobbby was fucking her from behind.
Ralph: Totally Awesome!
Billy: Yea, I changed her name in my phone to Harriet Tubman
The route, or system of back streets taken when you want to avoid the main arterial roads and heavily trafficked areas of your Town/Municipality in order to ride dirty.
Tubman: Wanna smoke this blunt in the car?
Truth: Hell yeah
Tubman: Wanna smoke this blunt on the way to Taco Bell?
Truth:Yes, but lets take the underground railroad, cops are out in full force Friday night.
Was neither underground nor a railroad. It was the different ways that Southern slaves escaped their masters by getting help from abolitionists to lead them to freedom in the North. Made famous by Harriet Tubman.
Toby: We gots ta gets free I her da massa's call!
Chicken George: Hopes we kan finds hep in da underground railroad!
A legion of anal driven women using horse cock size strap-ons as means of their sexual intercourse, form a circle of consecutive anal penetration. It is at this point that each member donkey punches the participant in front of them forcing defication. Said feces is then tossed gently and accurately into the center of the circle where a concetric circle of outward facing males who are in fact beating off vigorously, racing each other for their nut. The loser's punishment is to crawl through a tunnel made by the legs of the participants while they each take turns shitting on him. *note that the loser has to crawl slowly and with their back to the floor, and mouth open wide.*
-"Hey, since we have nothing else to do today 20 horse cock strap-ons, wanna take a ride on the secret The Underground Railroad today?"
-"Yeah man, that sounds great, just don't let any weirdos in this time!"