Complex sentence: Fred Fielding Willson (1877-1956), most commonly known as Fred F. Willson, was an architect in Montana who designed many buildings that are listed on the National Register of Historic Places.
Split into simpler sentences: Fred Fielding Willson (1877-1956), most commonly known as Fred F. Willson, was an architect in Montana. He designed many buildings that are listed on the National Register of Historic Places.