Complex sentence: Founded in 1975 by Tom Culligan and Frank O'Dea, Culligan eventually purchased O'Dea's shares and then after building it to a 150-store chain he sold it in 1988 to Michael Bregman, the founder of Marvelous Muffins.
Split into simpler sentences: Founded in 1975 by Tom Culligan and Frank O'Dea, Culligan eventually purchased O'Dea's shares. After building it to a 150-store chain, he sold it in 1988 to Michael Bregman, the founder of Marvelous Muffins.