I have not been able to locate a pension application in his name, but, a Goggle Search Anthony Southgate Butt came up with these two finds:

http://mormonhistoricsites.org/wp-content/uploads/2013/05/mhs1.1WoodsSpring2000.pdf

See paragraph one and Note 1.

……….

1849 29 22
Virginia, USA

Source: 1850 US Federal Population Census
Note: Anthony is shown as 10 and Henry J. as 1 on the 1850 census, but on 1860 "Antony" is 11 and Henry is 19 and a farm laborer. So I think the children's ages were flipped on the 1850 census. I'm listing Henry as the oldest due to his farm labor desig nation in 1860. Neither are listed in the 1870 household.
From the internet, Rose C. Brown [Rosec8569 atatat aol.com] writes that "James Anthony Butt (1896-1976) m. Marie Teresa Carty (1900-1974) on 4/4/1923. They are buried in St. Mary's Cemetery, Norfolk. Also there are J. Aubrey Butt 1873-19 25 and Anthony S. Butt 1842-1891. The "S" is for Southgate so there may be a connection to your line since that is an unusual name. My family line is Carty but also interested in Butt line. -Rose"

http://hawkofgeorgia.com/webtrees/individual.php?pid=I1088&ged=20061130s.ged