Interstate 75 in Georgia

The general routing of I-75 within Georgia was originally developed as the western routing of the Dixie Highway. The western route of the Dixie Highway as designated in 1916, followed present-day US 41 south from the Tennessee border through Atlanta and Macon south to Echeconnee, Georgia. The section that would become US 41, I-75's direct predecessor, from Echeconnee south through Perry and Valdosta to the border with Florida was paved beginning in 1919 and was later designated as a part of the Dixie Highway in 1924. In 1926, the western route of the Dixie Highway following the newer Perry and Valdosta route was officially designated as US 41. By October 1929, the majority of US 41 was paved in Georgia, the only sections that were not paved at that point were between Fort Oglethorpe and Ringgold, and another on the south side of Calhoun.[13]

The highway that would eventually become I-75 in Georgia was an unnamed expressway that was open in 1951 from the southern part of Atlanta to University Avenue. It was projected from University Avenue to Williams Street in Downtown Atlanta. This expressway was open from Williams Street to what is now the northern end of the Downtown Connector. It was also proposed from the Downtown Connector to the northwest part of Atlanta.[14][15] By late 1953, this expressway was signed as US 19/US 41 as far north as Lakewood Avenue. It was under construction from the Downtown Connector to Howell Mill Road. It was proposed from Howell Mill Road to the northwest part of Atlanta.[15][16] By mid-1954, the expressway was signed as SR 295 from Lakewood Avenue to University Avenue. It was under construction from the Downtown Connector to US 41/SR 3E, just north of West Paces Ferry Road.[16][17] By mid-1955, the highway was under construction from University Avenue to Glenn Street. It was open from Williams Street to US 41/SR 3E in the central part of Atlanta.[17][18] By mid-1957, the highway was opened from University Avenue to Glenn Street. It was also open from Williams Street to US 41/SR 3E in the northwest part of Atlanta.[18][19]

By the middle of 1960, a short segment southeast of Williams Street was open.[19][2] By mid-1963, I-75 was signed. It was open from the Florida state line to US 41/SR 7 in Unadilla. It was under construction from Unadilla to just north of the Crawford–Bibb county line. It was open from SR 148 in Bolingbroke to US 23/SR 42 north-northwest of Forsyth. It was open from Glenn Street to Washington Street in Downtown Atlanta. It was under construction from US 41/SR 3 in the northwest part of Atlanta to its northern interchange with I-285. It was also under construction from SR 53 in Calhoun to the Tennessee state line.[2][3] Between 1963 and 1965, it was open from US 41/SR 7 in Unadilla to Hartley Bridge Road south-southwest of Macon. It was proposed from Hartley Bridge Road to I-16 in Macon. It was under construction from I-16 to its northern interchange with I-475 near Bolingbroke. It was open from Bolingbroke to near Forsyth. It was under construction from there to SR 155 south of McDonough. It was proposed from there to SR 54 in Morrow. It was under construction from Morrow to US 19/US 41 west of Morrow. It was proposed from that interchange to SR 331 in Forest Park. It was open from Forest Park to West Paces Ferry Road in northwest Atlanta. It was under construction from there to SR 120 in Marietta. It was proposed from Marietta to SR 140 in Adairsville. It was under construction from Adairsville to SR 53 in Calhoun. It was open from Calhoun to the Tennessee state line.[3][20] In 1966, the highway was open from the Florida state line to its southern interchange with I-475 near Macon. It was open from I-16 to US 23/SR 42 near Forsyth. It was open from Forest Park to its northern interchange with I-285.[20][21] In 1967, it was under construction from US 80/SR 74 to I-16 in Macon. It was under construction from near Forsyth to the US 19/US 41 interchange west of Morrow. It was open from Forest Park to SR 120 in Marietta. It was under construction from SR 120 to Allgood Road in Marietta.[21][22] In 1968, the highway was open US 23/SR 42 near Forsyth to SR 20 in McDonough. It was under construction from McDonough to SR 54 in Morrow. It was open from Morrow to Allgood Road in Marietta. It was under construction from US 411/SR 61 near Cartersville to SR 140 in Adairsville.[22][23] In 1969, the highway was under construction from its southern interchange with I-475 to I-16 in Macon. It was open from I-16 to Allgood Road in Marietta.[23][24]

A section of I-75 in Cartersville.

In 1971, it was open from the Florida state line to Allgood Road in Marietta.[25][26] In 1973, it was under construction from Marietta to SR 92 in Acworth.[27][28] In 1974, the highway was under construction from Emerson to US 411/SR 61 near Cartersville.[28][29] The last segment of I-75 in Georgia, located between Emerson and Cartersville, opened on December 21, 1977.[30][31]

Much of the work to widen interstates across Atlanta including I-75 from six to eight lanes and the Downtown Connector to 10 lanes including the elimination of sharp curves and grades, left-hand exits, excessive interchanges, and short acceleration/deceleration lanes, took place in the 1980s. Construction began with widening I-285 first, beginning in 1976, continued to the radiating expressways, and concluded with the depressed sections of the Downtown Connector which were completed in 1988. I-75 widening from I-285 and Aviation Boulevard to the Downtown Connector was completed by late 1984. I-75 widening from the Brookwood Interchange to the Chattahoochee River and Cobb County line was widened in the early 1980s and completed by 1985. Work on the Downtown Connector portion began in 1984, and included redesigning the massive interchange between I-20 and I-75/I-85 and the design and construction of 55 bridges over the connector portion alone.[32] The project was completed in November 1988.

View of southbound I-75 at Jonesboro Road. Overhead signs are visible along the South Metro Express Lanes located in the freeway's median.

In addition to the general-purpose lanes added in the 1980s, provisions for high-occupancy vehicle lanes (HOV lanes) and dedicated onramps at Williams Street, Piedmont Avenue, and Memorial Drive were built and were subsequently converted to HOV usage in 1996 on the Downtown Connector. In 1996, HOV lanes were also added from I-285 on the south side of Atlanta to I-285 on the north side of Atlanta.

In 1998, the portion of I-75 that from the Chattahoochee River north to the Tennessee state line was named the Larry McDonald Memorial Highway.[33] Larry McDonald, a conservative Democratic representative to Congress, was aboard Korean Air Lines Flight 007 when it was shot down by the Soviet Union on September 1, 1983. He was the only sitting Congressperson to be reportedly killed by the Soviets during the Cold War. I-75 was also designated as the Horace E. Tate Freeway between I-85 to I-285 northwest of Downtown Atlanta, in honor of Horace Tate, who was a state senator in 1974.

Until 2000, the state of Georgia used the sequential interchange numbering system on all of its Interstate Highways. The first exit on each highway would begin with the number "1" and increase numerically with each exit. In 2000, the Georgia Department of Transportation (GDOT) switched to a mileage-based exit system, in which the exit number corresponded to the nearest milepost.[34][35]

In March 2007, I-75's HOV ramp serving Northside Drive in Atlanta was the site of the Bluffton University bus crash where 7 out 35 people on board the bus were killed.[36]

The highway had a lane widening project completed in 2011, allowing the entirety of the Interstate in Georgia to be three lanes in each direction.[5] On January 28, 2017, the new Peach Pass-only South Metro Express Lanes from SR 155 to SR 138 and I-675, opened.[37] On September 8, 2018, new Northwest Corridor Express Lanes from the I-285/I-75 interchange to Hickory Grove Road and from I-75/I-575 interchange to Sixes Road have opened, the lanes require a Peach Pass to use.[38]