What country was Edwin Hubble a citizen of?

Edwin Hubble was a citizen of the United States. He was born Edwin Powell Hubble on November 20, 1889, in Marshfield, Missouri, and became one of the leading American astronomers of the twentieth century.

Hubble studied at the University of Chicago and later earned a Rhodes Scholarship to the University of Oxford. After serving in the United States Army during World War I, he joined Mount Wilson Observatory in California in 1919. His major astronomical work, including observations of distant galaxies and their redshifts, was carried out from American observatories.

A common mix-up is to confuse Hubble's nationality with his time in England. He spent several years at Oxford, where he studied law and later returned to astronomy, but that education did not make him British. His name is now especially associated with the Hubble Space Telescope, launched in 1990 and named in his honor.