1900 US Census Cleveland Twp, Ward 33, Cuyahoga Co., Ohio, ED 161, Sheet 2, Page 291A
Census taken June 2, 1900
Address: 21 Fulton Street
All members of this family can can read, write, speak English.
Gillespie, J. B., Sept 1864, 35, married 6, Scotland, Scotland, Ireland 1865, 25, Laborer Warehouse, 0, Rents a house.
Gillespie, Martha E. Apr. 1859, 41,married 6, OH, OH, PA, schoal [school?], Martha has given birth to 3 children and 3 were living.
Ollom W.R., son, May 1876, 24, single, OH, WV, OH, Soldier
Ollom Chal R., son, May 1878, 22, single, OH, WV, OH, Clerk in office, 0
Ollom Franklin E., son, May 1880, 20, single OH WV, OH, Clerk in office, 0
Gillespie R. C., boarder male, Oct 1872, 27, Wd, PA, Scotland, Ireland, Day laborer, 0

From the look of the birth information, RC Gillespie, the boarder, may be a brother.
I notice that his birth and immigration information are a little muddled. I'm going to assume that he immigrated at the age of 10, not 1, since they noted he had been in the country 25 years.

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The 1910 Census lists John as born in Ohio and Martha as born in ENG.
1910 Census Ohio, Cuyahoga Co., East Cleveland, ED 0017 - Visit 0082
Gillespie, John B., 44, OH
Martha, 50, Eng,

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1920 Census Ohio, Cuyahoga Co., Cleveland City, ED 90 - Sheet 60B, Jan 12th
Boarders with Pelton, Marshal, 57
Flora, 54
Lula age 33
Gillespie, John, Roomer, 55, 1909, NA, 1919, read & write, Born: Scotland, Father: Scotland, Mother: England, Cashier in a Restaurant, works for a Salary.
Martha, Roomer, 60, Born: OHIO, Father: PA, Mother: OH, doesn’t work.

Son Charles “Ross” Ollom married Flora Ruth Pelton. I suppose these people could be her parents. Charles and wife Ruth named their child, born 1909, Charles Marshall Ollom.