Complex sentence: It was conceived and built under President Roosevelt's direction during 1939-40 on 16 acres (65,000 m²) of land in Hyde Park, New York, donated by the President and his mother, Sara Delano Roosevelt.
Split into simpler sentences: It was conceived and built under President Roosevelt's direction during 1939-40. Built on 16 acres (65,000 m²) of land in Hyde Park, New York, donated by the President and his mother, Sara Delano Roosevelt.