Complex sentence: In 1880 he formed a partnership with Henry J. Meier, Donaldson and Meier, that lasted until Meijer's death in 1917, and in fact the firm continued under the name "Donaldson and Meier" until into the 1930s.
Split into simpler sentences: In 1880 he formed a partnership with Henry J. Meier, Donaldson and Meier. Though Meier died in 1917, the firm continued under the "Donaldson and Meier" until the 1930s.