He was naturalized as a citizen of the United States in 1918. His naturalization papers give his name as George Percy Grainger. He was born 8 July 1882 in Melbourne, Australia. He emigrated to the United States on 1 September 1914, arriving in New York City. 
Percy was greatly affected by his mother's suicide, which occurred 30 April 1920. Apparently, she jumped from the widow on the 13th floor of the Aeolian Hall Building in New York City.
Ten years later, on 9 August 1928, he married Ella Viola Strom in Hollywood, California.
His death came 20 February 1961 at White Plains, New York. He was 78.
White Plains, N.Y. (AP)--Composer Percy Grainger, whose smaller compositions and arrangements of English folk tunes brought him fame on two continents, died Monday in White Plains Hospital. He was 78.
Grainger was known by pops concert-goers for such works as "Molly on the Shore," "Shepherd's Key," "Country Gardens," and "Handel in the Strand."
He was also a concert pianist, having appeared in public for the first time at the age of 10 as a child prodigy.
He used the name Percy Aldridge Grainger, but he was born George Percy Grainger in Melbourne, Australia, July 8, 1882. He went to England in 1900, and came to the United States in 1915 and remained. He had a home in this New York City suburban community.
↑ "New York, County Naturalization Records, 1791-1980," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:QLRG-1NQD : 5 November 2019), George Percy Grainger, 1918; citing Naturalization, New York, United States, citing multiple County Clerk offices of New York; FHL microfilm 005411338.
↑ Percy Grainger's Mother is Killed. 13-Story Fall is Believed Suicide Jump. The Oregonian, Monday, May 1, 1922, Portland, OR, page 1.
↑ "California, County Marriages, 1850-1952," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K8NL-6QD : 8 December 2017), George Percy Grainger and Ella Viola Strom, 09 Aug 1928; citing Los Angeles, California, United States, county courthouses, California; FHL microfilm 2,074,719.