Context: Donald Wills Douglas, Sr. built a plant in 1922 at Clover Field (Santa Monica Airport) for the Douglas Aircraft Company. In 1924, four Douglas-built planes took off from Clover Field to attempt the first aerial circumnavigation of the world. Two planes made it back, after having covered 27,553 miles (44,342 km) in 175 days, and were greeted on their return September 23, 1924, by a crowd of 200,000 (generously estimated). The Douglas Company (later McDonnell Douglas) kept facilities in the city until the 1960s.

Question: Who built a plant in Clover field?
Answer: Donald Wills Douglas, Sr

Question: What company was the structure at Clover Field for?
Answer: Douglas Aircraft

Question: What did Clover Field built airplanes attempt the first of?
Answer: aerial circumnavigation of the world

Question: The Douglas Company had facilities in Santa Monica through what decade?
Answer: 1960s

Question: How Many Planes returned from the circumnavigation in 1924?
Answer: Two

Question: In what year was Donald Wills Douglas, Sr. born?
Answer: Unanswerable

Question: How many people worked for the Douglas Company?
Answer: Unanswerable

Question: In what year was the Douglas Company renamed as McDonnell Douglas?
Answer: Unanswerable

Question: Who was one of the pilots that flew four Douglas-built planes attempting the first aerial circumnavigation of the world?
Answer: Unanswerable

Question: In what decade did Donald Wills Douglas, Jr. die?
Answer: Unanswerable