The county unit system resulted in georgia politicians doing most of their campaigning

The county unit system was established in 1917 when the Georgia legislature, overwhelmingly dominated by the Democratic Party, passed the Neill Primary Act.
Election day in Kingsland, Camden County, in the early 1960s, before the advent of voting booths. Georgia's elections were governed by the county unit system, which gave more weight to rural votes than to urban votes, until 1962. Even though they were home to a minority of Georgians, rural counties usually decided the winners of statewide elections.
County Unit System
This act formalized what had operated as an informal system, instituted in Georgia in 1898, of allotting votes by county in party primary elections. (A primary election is held before a general election in order to determine each political party's candidates for the general election.) The county unit system continued to be used in Democratic primaries for statewide office and selected U.S. House districts until the early 1960s.