Complex sentence: It was formed in San Antonio in 1987 by Rick Archer, Tim Blonkvist, Robert Schmidt, and Madison Smith; in 1992 they were joined by Bob Shemwell.
Split into simpler sentences: It was formed in San Antonio in 1987 by Rick Archer, Tim Blonkvist, Robert Schmidt, and Madison Smith. In 1992 they were joined by Bob Shemwell.