"United States Census, 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MXQW-395 : 12 April 2016), Alecksander Mckay in household of Robert Coldwell, Cincinnati, ward 3, Hamilton, Ohio, United States; citing family 3, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).
Robert Coldwell 28 Scotland
Agness Coldwell 28 Scotland
James Coldwell 1 Ohio
Neal Mckay. 76 Scotland
John Mckay 25 Scotland
Alecksander Mckay 30 Scotland
Neal Mckay 23 Scotland
(Coldwell=Colville) His sister Agnes and brother in law.
1870 US Census
"United States Census, 1870," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M6W1-BFL : 12 April 2016), Alexander Mckay, Illinois, United States; citing p. 11, family 83, NARA microfilm publication M593 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 545,793.
It may be possible to confirm family relationships with Alexander by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Alexander: