Don't know "how" they were created but here they are,
Bylaw 322. GEOGRAPHIC BOUNDARIES OF DISTRICTS

Section 1: The Piedmont District is defined as - East of Georgia /South Carolina border. West of US 321 from NC border to SC 121 at Chester. SC 121 from Chester to Johnson. US 25 from Johnson to I - 20.
North of I - 20. South of the SC/Georgia border.

Section 2: The Mid-State District is defined as - Eastern boundary of Piedmont District west of I - 95, but not to exclude the Florence Soccer Association. North of the SC/Georgia border. South of the NC / SC border.

Section 3: The Coastal District is defined as - East of I - 95. West of the Atlantic Ocean. North of the SC/Georgia border. South of the NC / SC border.

Section 4. The districts may be realigned or new districts established by a two-thirds vote of the Board of Directors.