Was your Earl a professional military man? If yes, I've got information on him. If not or if you don't know, there were two Earl McGuire's.
There was an Earl McGuire who was born 22 April 1894 in Indianapolis, Marion, IN. He was taken in by the Millhouse's. He married an Esther Asenath Lund 16 Sept 1916 in Los Angeles. He died 14 Nov 1968 in Exeter, Tulare, CA.
Source: McGuire 123 family tree, trees.ancestry.com/tree/34931093/person/18722179853 .Most larger libraries provide free access to Ancestry.
The other Earl that I found was living in Bloomington, Monroe, Indiana in 1900 with his family.
John Mcguire, b. IN June 1872, marr 6 yrs, ru__ derrick.
Maud, wife, b. IN Oct 1878.
Earl, b. March 1895, IN.
Pearl, b. Jan. 1898, IN.
Ruby, b. Dec 1899, IN.
In 1910 the family was living in Bloomington, Monroe, IN.
John Mcguire, b. IN, 38, marr 16 yrs, latho man stone mill.
Maude E., wife, b. IN, 31, had given birth to seven children & all alive in 1910.
Earl, b. IN, 15.
Pearl, b. IN, 12.
Ruby, b. IN, 10.
Roy, b. IN, 9.
Freda, b. IN, 4.
Frank, b. IN, 3.
Clovis, son, b. IN, 11/12ths.
Earl B. McGuire
Born: abt. 1893, Linton, Indiana
Enlistment: 18 Sept. 1914, Columbus Barracks, Ohio
Military Branch: Ohio
Comments: Headquarters Troop 8 Cavalry to 28 Sept. 1917;
Wagon Co. Ammunition Train 2 Divisiton to --;
Co. G 3 Ammunition Train to Discharge Corporal 15 July 1917;
Sergeant 12 April 1918;
Private 1 Nov 1918;
Corporal 13 July 1919. Champagne-Marne; Aisne-Marne; St. Mi
Source: Ohio Soldiers in World War I 1917-18.
Earl B. McGuire
Serial #: 748720
Residence: Springfield, Ohio
Military: Regular Army
Enlistment Location: Columbus Barracks, OH on 18 Sept. 1914
Birth: Linton, IN
Assignment Comments: same as above except for St. Mihiel; Meuse-Argonne; Defensive Sector. American Expeditionary Forces 16 March 1918 to Discharge Honorable 21 Oct 1919. Immediate reenlistment.
Source: Ohio Military Men 1917-18.
In 1920 Earl was living at Ehrenbreitstein, Germany, Military & Naval Forces.
Born: abt. 1895, Indiana
Marital Status: Single
Father's Birthplace: IN
Mother's Birthplace: IN
From: 2109 Columbus Ave., Springfield, OH
In 1930 he was living in Fort Winfield Scott in San Fran. Soldier U.S. Army, 36, single.
I didn't find his death info. Let me know what you think about the two Earl's.