[2] Authorized by the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA), I-73 was established as a north–south high-priority corridor from Charleston, South Carolina, to Detroit, Michigan.

[3][4] In 1993, the proposed route through South Carolina followed US 1 and US 52 to Florence, with 73 miles (117 km) of new road in Marion and Horry counties, and following US 17 from North Myrtle Beach to Charleston.

[9] At one point, South Carolina intended to have stop lights and driveways on I-73, but the National Highway System Designation Act, passed in 1995, required I-73 to be built to Interstate standards.

[10][11] In 1998, Representative Mark Sanford introduced an amendment to the Transportation Equity Act for the 21st Century (TEA-21) that changed the southern terminus of I-73 to Georgetown.

In 2003, the South Carolina General Assembly approved a resolution asking that the Conway Bypass (SC 22) be designated as I-73 which changed the southern terminus from Georgetown to Briarcliffe Acres.

[13] In 2003, SCDOT went through a series of public meetings and came up with five routes: In late 2003, the state decided to go with option three and started environmental impact studies in 2004.

[23] On September 15, 2011, South Carolina road commissioners approved an $11.5-million (equivalent to $15.1 million in 2023[19]) plan to rebuild a bridge in Dillon County, near Latta.

[24] On November 7, 2011, Myrtle Beach city council member Wayne Gray asked area elected officials to consider using Road Improvement and Development Effort (RIDE) funds to pay for a portion of I-73.

[25] In June 2012, Miley and Associates of Columbia recommended improvements to SC 38 and US 501 to create the Grand Strand Expressway (GSX), a position long held by the Coastal Conservation League, which asked for the study.

After the announcement, SCDOT's Transportation Commission chairperson Woody Willard of Spartanburg said "I-73 is important for economic development and safety, as a quicker way to evacuate people from the Grand Strand when a hurricane approaches.

[30] However, South Carolina Governor Henry McMaster’s 2024 executive budget, which was released in early-January 2024, did not include any funding for building the route.

"[31][32] Despite the lack of funding, Horry County still plans to work on their section of the future freeway pending the passing of the RIDE IV program.