Short answers, pulled from the story.
Mercury Records was founded in Chicago in 1945 by Irving Green, Berle Adams, Ray Greenberg, and Arthur Talmadge. The label distinguished itself early by promoting records through jukeboxes rather than radio airplay, which lowered costs and let it compete with larger established labels.
The Mercury Living Presence technique used a single microphone to record symphony orchestras, introduced in 1951 under recording engineer C. Robert Fine and recording director David Hall. New York Times critic Howard Taubman described the resulting sound as "being in the living presence of the orchestra," which gave the series its name. In late 1955, Mercury expanded to three omnidirectional microphones for stereo recordings on three-track tape.
Mercury Records released the first cassette music tapes in the United States in July 1967, marketing them under the name Musicassettes. This made Mercury the first American record label to distribute music in cassette format.
After Seagram bought PolyGram in late 1998 and absorbed it into Universal Music Group, Mercury Records was closed and folded into the Island Def Jam Music Group. Its pop roster moved primarily to Island Records, hip-hop acts went to Def Jam Recordings, R&B acts shifted to Def Soul Records, and the country division became Mercury Nashville Records. Mercury was relaunched in 2007 under David Massey as President and CEO, made defunct again in 2015, and then acquired by Republic Records on the 11th of April, 2022.
In 1947, Patti Page recorded "Confess" at Mercury singing both her own voice and the answer parts because the budget was too small to hire a second singer. This became the first documented use of overdubbing on tape, even though overdubbing had appeared occasionally on 78-rpm discs in the 1930s.
Mercury Records became a leading hard rock label by signing Bon Jovi, Def Leppard, Kiss, the Scorpions, Cinderella, Thin Lizzy, and Rush. The label absorbed Kiss, Donna Summer, and the Village People when it took on the Casablanca Records catalog. In Europe, most of those rock acts appeared on the related Vertigo Records label.