United Airlines Boeing 737-300

United Airlines Boeing 737-322, N312UA, is shown arriving at Orlando on November 11, 1991 wearing the carrier’s 1974-introduced livery with updated enlarged name titles.

(Photo credit: Lewis Grant)

United Airlines Boeing 737-322, N344UA, is shown arriving at Los Angeles on January 20, 2002 wearing the carrier’s 1993-introduced livery.

(Photo credit: Jason Whitebird)

United Airlines Boeing 737-322, N372UA, is shown departing Los Angeles on January 25, 2009 wearing the carrier’s 2004-introduced livery.

(Photo credit: Ben Wang)