Complex sentence: Liebenberg and Kaplan (L&K) was a Minneapolis architectural firm founded in 1923 by Jacob J. Liebenberg and Seeman I. Kaplan, and was one of the Twin Cities' most successful and prolific architectural firms.
Split into simpler sentences: Liebenberg and Kaplan (L&K) was a Minneapolis architectural firm founded in 1923 by Jacob J. Liebenberg and Seeman I. Kaplan. Liebenberg & Kaplan became one of the Twin Cities most successful and prolific architectural firms.