Guam was a station for American merchant and warships traveling to and from the Philippines (another American acquisition from Spain) while the Northern Mariana Islands were sold by Spain to Germany for part of its rapidly expanding German Empire. A U.S. Navy yard was established at Piti in 1899, and a United States Marine Corps barracks at Sumay in 1901. A marine seaplane unit was stationed in Sumay from 1921 to 1930, the first in the Pacific. The Commercial Pacific Cable Company built a telegraph/telephone station in 1903 for the first trans-Pacific communications cable, followed by Pan American World Airways established a seaplane base at Sumay for its trans-Pacific "China Clipper" route.