Individual Details

It is known that Eugene's brother Rodney changed the spelling of the name to "Hayden". Eugene may have started the trend. In 1910, his father was listed in the census as Haden, but Eugene appears as Hayden.
1910 Census. Peoria Ward, Peoria Co, IL, Hh 2
Living at 707 E. Nebraska St.
Eugene S. Hayden, age 24, married once for 4 years, b. IL parents b. KY, Appraiser for a Loan Company
Pearl L., wife. No children., b. IL

No luck finding Eugene in 1920.

There was more than one Eugene Hayden of the approximate age, but not as close as this one and none other born in Illinois with father born Kentucky:
In Chicago, Cook Co, IL, Hh 46
Living in a multi-family home at 2015 Ainslie Street:
Eugene Hayden, 43, married at age 33, b. IL, father b. KY, mother b. IL, real estate salesman
Wilda, Wife, 42, married at age 32, b. IL, father b. WI, mother b. IL
Lelia, Daughter, age 5 years and some months [blot]

Birth	Feb 1887	Illinois
Death	Ca 1948	?Chicago

Father	Eugene S. Haden (1850 - 1927)
Mother	Catharine "Kate" Sherbine (1852 - 1924)
Sibling	Walter C. Haden (1879 - 1945)
Sibling	William H. Haden (1882 - 1929)
Sibling	Rodney Earl Hayden Sr. (1891 - 1967)