Yes. In the 'Scott Specialized Catalog of US Stamps' the oldest US stamps have a subcategory for cancellations. Special cancellations can increase the value of older stamps. 'Railroad' is one of those cancellations.
Note: You reference a 20 Cent Special Delivery stamp. A 20 cent Special Delivery wasn't issued until 1925. A 'So. Rwy' may add a little value to the stamp, but I wouldn't expect much.
The Madras and Southern Mahratta Railway was founded on January 1, 1908 when both the Madras Railway and the Southern Mahratta Railway merged. It was then merged again in 1951 with the Mysore State Railway and the South Indian Railway forming the Southern Railway.
Elkhorn Southern Railway ended in 1911.
Southern Manitoba Railway was created in 1999.
Abbeville Southern Railway was created in 1892.
Abbeville Southern Railway ended in 1893.
Norfolk Southern Railway was created in 1990.
Washington Southern Railway ended in 1920.
Washington Southern Railway was created in 1890.
Montana Southern Railway ended in 1941.
Montana Southern Railway was created in 1917.
Columbus Southern Railway ended in 1896.
Columbus Southern Railway was created in 1886.