These statements are describing
a. georgia's canal system.
b. georgia's freeway system.
c. georgia's railroad system.
d. the georgia department of transportation.

Here are the statements: 
-By the mid-1830’s routes connected Athens, Augusta, Macon and Savannah

-Led to the construction of Marthasville in 1845

-Georgia claimed more miles than any other state in the Deep South by 1850

These statements are describing Georgia's's railroad system.