Complex sentence: Plankinton is associated with the Milwaukee Railroad company with Frederick Layton and financed the construction of the first Milwaukee public library in 1882, which at the time was on Grand Ave between Fourth and Fifth Streets.
Split into simpler sentences: Plankinton is associated with the Milwaukee Railroad company with Frederick Layton. Plankinton financed the construction of the first Milwaukee public library in 1882, which at the time was on Grand Ave between Fourth and Fifth Streets.