If you don't know if John or James you should look for Patrick first. Co. Kildare is a member of a Irish History Foundation www.rootsireland.ie
and there are Parish's that could provide a record for you.
You can look for Patrick with surname and year of birth,
you might get several? The above website is a pay to view
and get a record of birth. A birth record for Patrick will give you his father's name, mother's name and maiden name, and place/parish and a date. Once you have both parents names you could look for a marriage record which would give you the father's names of partners.
Once you know the correct name and Parish you maybe able to find more information?
Griffith Valuation took place in 1850 in Kildare. There were no McMann's in Kildare at that time.
There is 1 Blair (marriages usually took place in wife's parish so maybe that is why Kildare)
William Blair, Parish of Leixlip, Townland Leixlip (Town of
Leixlip) Poor Law Union Celbridge. Tenant of Henry Beere
#19 a house shared with Michael Daly, Michael Walsh and Thomas Keegan
This is something that in 5 years of looking through Griffith I've never seen before. Usually people occupied their own homes and then shared land. That is common.
A Poor Law Union, later to be the Civil Registration
District from 1864 would contain all Parish's,towns and townlands within a 12 mi. radius and can cross over into
another county. However, I checked these counties and only 1 had any McManns, there are 18 in Kings/Offaly.
Patrick McManns, Parish of Birr (Parsonstown), Townparks
Poor Law Union of Parsonstown, tenant of William Wellwood
#60 house, yard and small garden
see the others at www.askaboutireland.ie
The Parish record for Birr RC are 1838-1913, marriages 1838-1905. Church of Ireland 1760-1899, marriages 1760-1900
and deaths 1786-1984.
These parish records are at the Irish History Foundation and are available on line for a fee, as above.