It was good for you to post the information you have already found, that eliminates posting it for you, although most volunteers will revisit those Census to see just what is there themselves.I almost always do, you'd be surprised what is missed...and what others post WRONGLY.
When you post, post the critical information also.The persons date of birth is always helpful, especially when other information is not presented and the name is common.
For other researchers: Yes, the President William McKinley was family (brother).Pg's 40/41 has David:
David was a US Consul and Consul General for Hawaii...you would think there would be quite an established history of him and his family.
The California Deaths:
Ida Morse, died 2/3/1913, age 47(1865/1866), died LA County
Ida Morse, died 1/9/1923, age 60(1862/1863) spouse first initial "K," "M?", died Stanislaus County.
--The 1900 Census for San Francisco County, 1578 Hill? Street
George Morse, born August 1870, born in CA to father born in MA, mother England
Ida H, Oct 1870 in CA to both parents born in OH
Marjorie M, dau, born Feb 1895 in CA.
The 1910 Census for Oakland, Alameda CA
Harry R. Cooper, age42, born in CA to father born in PA, mother in Michigan, stationer/own store.
Ida M (McKinley?), age 38, born in CA to father born in Ohio, mother in PA, second marriage
Marjorie M, age 15, born in CA to both parents born in CA.
---This Ida and Marjorie match much of the criteria; however, it would need to be proved that this Ida had divorced and remarried.
--The California Deaths identify an Ida M Cooper, died 3/30/1911 in Alameda County, she was 40 years of age...matches criteria.
The other person identified finding:
In 1920 George and Marjorie were living in Los Angeles...
George Morse, b. CA, 49, W, driver creamery.
Margaret Morse, mother, bo. NY, 74, W
Margery Morse, dau, b. CA, 16.
---This CAN NOT be the correct persons.
This George, born in CA to both parents born in New York--wrong parental birth locations.
Margaret, mother, born in New York, wrong parental birth location.
Margery, dau, age 16.This would make her birth being 1903/1904.The REAL MARJORIE was born 1894/1895.Her mother's birth location was identified as being in New York...the Correct Marjorie's mother was born in CA.
There are 28 family trees posted that include David Allison McKinley. He is identified as birth: 23 Nov 1829 in Fairfield, Columbiana; death: 18 Sep 1892 in San Francisco, CA.Only a couple identify Gibson.None really identify Ida.So, I'm guessing a number of them filed their family tree by just clicking on a leaf...I would just LOVE to add some false name and info and see how many post it to their trees without any verification.
William Perry and Gibson McKinley:
BUT, I found no PROOF.There are thousands of wrong/inaccurate speculations found in genealogy records.I always need the proof.
--As far as William, he is shown as being born on 10 Sep 1852 in HIles, Trumbull County, OH.I seriously doubt the person found in the 1900 census in Cincinnati is the correct person, born Feb 1853.The "correct" person isn't found in the 1880 census.The 1880 census shows 10 born between 1851 and 1855.
Because of the connection to the President, as well as his own political history, there should be at minimum a newspaper article concerning his death in San Francisco.There should be an obituary also..
----- add'l comments and background information for other researchers.------
The 1850 Census for Weathersfield, Trumbull Co. OH, enumerated 9/16:
David McKinley, age 20, born in Pennsylvania, Parents William 41, and Nancy (Allison) 40, both born in PA.All members born in PA.
Sibling: James, age 16.There is no "B.F." identified (see 1860).
The 1860 Census for White Oak, Eldorado Co, CA, enumerated 8/6:
D.A. McKinley (transcribed as McKenley), 30(1829/1830) Ohio, miner.
Nancy, 29 (1830/1831), PA
William 8(1851/1852), OH
James McKinley 26, OH; B.F. McKinley (male), 25, OH
The 1870 Census:I did a number of varied searches, without success.It is not unusual to not find a family in the census.Even today, thousands (or more) are missed.They could have been away and the enumerator missed them.The enumerator didn't find their home.The enumerator missed writing their notes upon the actual census forms.The census form was lost, not copied for transcription, the transcription missed this family, the transcription was wrong, the database "ate" their names, etc.To many reasons to identify.
1880 Census for Oakland, Alameda Co, enum 6/4:
David A, 50, born in Ohio, Coal and Wood dealer
Mineva(as written) N. age 48, PA
Ida Hellen(as written) 9(1870/1871), CA
--President McKinley was married to an Ida in 1871 (Was David's daughter named after his brother's wife?), also had a daughter Ida, born/died 1873.