Hi, I have found some info on both Catherine and Daniel which is going to change where you look.
1880 US census:Ward 12,Baltimore
Daniel Burnsage 35, born @ 1845 Ireland,married,spouse Catherine Burns,both parents born in Ireland,occ:foreman on lake Catherine Burns age 35,born @ 1845 Ireland,married,spouse Daniel Burns,both parents born in Ireland,occ:keeping house Mary Burns age 11,born @ 1869 Maryland Joseph Burns age 9,born @ 1871 Maryland Katy Burns age 7,born @ 1873 Maryland Daniel Burns age 6,born @ 1874 Maryland
1870 US census:Ward 18,Baltimore
Ellen Burns age 61,born @ 1809 Ireland,occ:keeps house Daniel Burns age 22,born @ 1848 Ireland,occ:labourer
1870 US census:Texas,8th District,Baltimore
John Manan age 25,born @ 1845 Ireland,occ:shoemaker Catherine Manan age 24,born @ 1846 Ireland,occ:keeping house Mary H Manan age 2,born @ 1868 Maryland Celia Manan age 10/12,born @ 1869 Maryland Mary Manan age 66,born @ 1804 Ireland
living at house #3(next door to Manans at #4 are:
Edward Burns age 65,born @ 1805 Ireland Bridget Burns age 50,born @ 1820 Ireland John Burns age 29,born @ 1841 Ireland William Burns age 13,born @ 1857 Maryland Julie Burns age 10,born @ 1860 Maryland *Edward and Bridget also have children Thomas age 28,Mary age 26,Hugh age 24,Ann age 22,Catherine age 20 and Henry age 18.
What you are going to have to do is locate the marriage between John and Catherine Manan to find out what Catherine's real maiden name was.Her and John must've married around or just after the Civil War in Baltimore. There are quite a few Burns families in Baltimore in the 1860s many of whom are probably related:
1860 US census Baltimore: Dennis Burns age 56 & family Ward 18 Thomas Burns age 16 Ward 3 James Burns age 53 & family Ward 12 Edward Burns age 44 & family Ward 8 Jane Burns age 70 & daughter Eliza Ward 18 Francis Burns age 68 & family Ward 14 Margaret Burns age 63 Ward 13 Ellen Burns age 45 Ward 18 * this may be Daniel's mum but I could not find Daniel anywhere in Maryland.I did find an Ellen with a son Daniel and other children in 1860 in Monroe,Orange co,NY.There is no way to know if this is correct Ellen unless you know name of some of Daniel's brothers.Curiously in 1880 census,I found an Ellen Burns age 65,widow,residing with her son Patrick age 34 so this may be Daniel's mom.You could get her death cert which may say where she was from.Also Daniel was naturalised so that would help too.But with Catherine you will have to find the marriage cert to locate her maiden name.Hope this helps,Kim