The Happy Bottom Riding Club, or Riding Club for short, was the name given to the crew lounge of the USS Enterprise-E by William T. Riker shortly before his departure to take command of the USS Titan. Previously the crew had simply continued to call the lounge Ten Forward after the USS Enterprise-D's lounge. (TNG novels: Resistance, Q & A, DS9 novel: Avatar, Book One)
The name came from a 20th century establishment on Earth; The original Happy Bottom Riding Club was run by a woman named Pancho Barnes in remote desert area of California near an airbase used to test fixed-wing aircraft. The club featured a ranch, rodeo field, dance hall and a restaurant. Barnes offered a free steak dinner to anyone who flew faster than the speed of sound, the first to take up the offer was Chuck Yeager. According to legend many of first astronauts were recruited at the bar.
It took Riker some time to convince Captain Picard to change the name, and after the name had been given Worf considered it to be a practical joke by the departing Captain Riker. (The Sky's the Limit short story: "On the Spot")
Other member's of the crew were far more enthusiastic, particularly the bar keep Jordan who carried on Barnes's tradition of attaching relics to the walls of the bar. Items on the wall included; A photo of Guinan in one of her hats, a portrait of Barnes, pictures of Enterprise-E crew members who'd been killed in action serving on the vessel, a horseshoe, a map of California noting the location of the original Riding Club, a copy of the original bar's liquor license, a mission patch from the Enterprise (NX-01), a replica of the dedication plaque from James T. Kirk's Enterprise and a d'k tahg donated by Captain Picard. Jordan would willingly tell anyone who dared ask the story behind each item. (TNG novel: Q & A)