Charles was born in 1880. His parents were Eastman Galpin and Emma (Nourse) Galpin. The family was living in Falls Church, Fairfax, Virginia in the 1880 census and the household members were:
Eastman J. Galpin 40
Emma Galpin 30
Mary Galpin 10
Ida Galpin 8
Harvey Galpin 5
Ray Galpin 4
Charles Galpin 4/12
Charles enlisted in the US Marines on 15 May 1896 in Fairfax, Virginia. He was serving aboard the USS Maine as a Private when it was sent to Havana, Cuba in Feb 1898 to help protect American interests there. The ship exploded on 15 Feb 1898 in the harbor of Havana in the USS Maine Disaster. Charles was uninjured and survived the explosion.
Charles married Mary V (Mamie) Penn in 1903 and together they had two children, Harry and Ruth. He died in 1954.
Sources
"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MC5M-KSX : 15 July 2017), Charles Galpin in household of Eastman J Galpin, Falls Church, Fairfax, Virginia, United States; citing enumeration district ED 37, sheet 311B, NARA microfilm publication T9 (Washington, D.C.: National Archives and Records Administration, n.d.), FHL microfilm 1,255,364.
"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MKLK-3QL : accessed 14 May 2020), Charles P Galpin, Precinct 9, Washington, District of Columbia, United States; citing enumeration district (ED) ED 187, sheet 6B, family 115, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 154; FHL microfilm 1,374,167.
"United States World War I Draft Registration Cards, 1917-1918", database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K6K7-GW6 : 26 August 2019), Charles Parker Galpin, 1917-1918.
"United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MNLP-6Y9 : accessed 14 May 2020), Charles Galpin, Washington, Washington, District of Columbia, United States; citing ED 237, sheet 1A, line 34, family 9, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 208; FHL microfilm 1,820,208.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XM2W-C15 : accessed 14 May 2020), Charles P Galpin, Washington, Washington, District of Columbia, United States; citing enumeration district (ED) ED 356, sheet 18B, line 86, family 296, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 303; FHL microfilm 2,340,038.
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:VTHX-T4C : 28 January 2020), Charles Galpin, Election Precinct 40, Duval, Florida, United States; citing enumeration district (ED) 16-28, sheet 4B, line 66, family 83, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 584.
"United States, Veterans Administration Master Index, 1917-1940," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:QPZX-S5FS : 27 October 2019), Charles P Galpin, 1 Jun 1901; citing Military Service, NARA microfilm publication 76193916 (St. Louis: National Archives and Records Administration, 1985), various roll numbers.
"Florida Death Index, 1877-1998," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:VV65-2L7 : 25 December 2014), Charles P. Galpin, 1954; from "Florida Death Index, 1877-1998," index, Ancestry (www.ancestry.com : 2004); citing vol. 1664, certificate number 16991, Florida Department of Health, Office of Vital Records, Jacksonville.