There is a John McGuire listed in Macon County, AL in 1840 census and the family is listed as John P Mcgaine (born in South Carolina) in Macon County, AL in the 1850 census. His wife is Nancy Chapman, born in VA, and they married in Russell County, Al in 1839. Their children in the 1850 census include Amandia, age 10; Georgean, age 8; For?Hida (Florida in 1870 census) age 6; Virginia, age 4; and Indana (Susan in 1870 census), age 3. The 1870 census shows Nancy McGuire as head of household with additional children Grissom, age 15; Tom, age 18; Allen, age 13; and John J, age 10. Later, part of this family line moves to Macon County, GA after 1910 while many remain in Macon County, AL. I am a descendant through William Allen McGuire.
John P McGuire served in Company E of the 21st Regiment, Alabama Infantry as a private. This regiment also fought at Spanish Fort and Fort Morgan and organized out of Mobile, so there may be some connection between the John you are searching and this family unit I am tracking.
Of note in regards to Macon, there are many instances of city and county names matching in GA though they are not in the same geographical location. It makes family tracking interesting and hard to keep straight.