Interstate 81 in Tennessee

The crossroads between US 11W and US 25E in old Bean Station in 1942 with signs showing distances to cities along each route.

Prior to the settlement of Tennessee by European Americans, a series of Native American trails existed in the area that I-81 now passes through.[11] Most of these were part of the Great Indian Warpath, which the Interstate follows for most of its length.[12] A lesser used trail reportedly existed east of this path, which became part of the Great Wagon Road, also known as the Great Valley Road.[13] The northeastern part of Tennessee was the first part of the state to be significantly explored and settled, with long hunters exploring much of the region during the 1760s and the first permanent settlements arising by the end of that decade.[14] The Great Indian Warpath from Knoxville to Abingdon, Virginia, became a wagon road known as the Old Stage Road, and was used extensively by early Tennesseans and travelers from other states.[15]

In 1911, a series of Tennessee businesspeople formed the Memphis to Bristol Highway Association to encourage the state to improve the network of roads that ran between Memphis and Bristol.[16] After the formation of the Tennessee Department of Highways and Public Works, the predecessor agency to TDOT, in 1915, the Old Stage Road was designated as part of the Memphis to Bristol Highway.[17] This section became part of the Lee Highway, an auto trail, in 1919.[18] When the Tennessee State Route System was established in 1923, this part of the Lee Highway became part of State Route 1 (SR 1), and the network of roads to the east that followed part of the Great Wagon Road became SR 34.[19] When the United States Numbered Highway System was formed by Congress in 1926, Lee Highway became US 11, and SR 34 was designated as US 511. Tennessee officials objected to this numbering scheme, and in 1929 successfully petitioned the American Association of State Highway Officials (AASHO) to redesignate US 11 as US 11W and US 511 as US 11E in an event that came to be known as "The Tennessee Split".[20]

The general location of the highway that became I-81 was included in the National Interregional Highway Committee's 1944 report, titled Interregional Highways, and a subsequent 1947 plan produced by the Public Roads Administration of the now-defunct Federal Works Agency. These blueprints recommended that it terminate east of Knoxville with the highway that became I-40.[21][22] During the planning phase, it was also suggested that the Interstate follow the corridor of US 11W from Knoxville to Bristol, but residents of Grainger County were opposed to this.[23] The alignment was reaffirmed in a map produced by the Bureau of Public Roads, the predecessor agency to the Federal Highway Administration, in September 1955.[24] I-81 was part of the original 1,047.6 miles (1,685.9 km) of Interstate Highways authorized for Tennessee by the Federal-Aid Highway Act of 1956, commonly known as the Interstate Highway Act.[25] The numbering was approved by the American Association of State Highway Officials on August 14, 1957.[2] That year, the Johnson City Planning Commission unsuccessfully lobbied to move the routing a few miles south between Morristown and Bristol to run closer to Johnson City and the Tri-Cities Regional Airport.[26]

I-81 in Tennessee roughly parallels US 11W, which had earned the nickname "Bloody 11W" and was the site of the deadliest collision in Tennessee history in 1972.[27]

The first stretch of I-81 in Tennessee to be completed was the one-mile (1.6 km) segment between US 11W and the Virginia state line, along with the southernmost 5.6 miles (9.0 km) of the Interstate in Virginia. Referred to at the time as the "Bristol Bypass", this section opened to traffic on November 20, 1961, along with I-381 directly across the state line.[28][29] Grading and bridge construction on the interchange with I-40 took place in the early 1960s, but this interchange was not opened to traffic until work on the approaches was complete.[30][31] The contract to construct the segment between the southern terminus with I-40 and US 25E near Morristown was awarded in June 1964,[32][33] and completed in December 1966, along with the connecting section of I-40.[34][35] Like much of the Interstate System in Tennessee, priority was generally given to completing sections in Middle and West Tennessee over East Tennessee. For this reason, most of I-81 was not constructed in the state until after the late 1960s.[36] The decision to prioritize other Interstate Highways was criticized by some due to the unsafe conditions and high accident rate on US 11W, which had earned the nickname "Bloody 11W" and was the site of the deadliest traffic collision in state history in 1972.[27][37][38] The slow progress on the Interstate became an issue in the 1966 gubernatorial election, when Democratic candidate John Jay Hooker accused primary opponent Buford Ellington, who served as Governor from 1959 to 1963, of neglecting the stretch allocated for Tennessee.[37] Ellington, who was elected that fall, responded with a promise to complete I-81 by 1971, the year the next governor would leave office, as well as improve US 11W.[39][40]

Contracts for construction of the stretch between US 25E near Morristown and US 11E near Mosheim were let in August 1967 and February 1968,[41][42] and the section opened to traffic on December 10, 1970.[43][44] Contracts for sections in Sullivan County were awarded throughout 1969,[45][46] and work on what became the final stretch of I-81 in Tennessee to be completed, the 43-mile (69 km) section located between US 11E and SR 126 near Blountville, began on July 7, 1969, in the southern part of that county.[47][48] The remaining Sullivan County portions were contracted for construction in December 1970 and March 1971,[49] and sections in Washington and Greene Counties were let in November and December 1971.[50][51] The last construction contract for I-81 in Tennessee, which was for the northernmost 5.8 miles (9.3 km) in Greene County, was awarded in March 1972.[52][53] The opening of the 9.6-mile (15.4 km) stretch between SR 126 and US 11W in Bristol was announced on December 23, 1972.[54][55] Once all remaining construction began, completion of I-81 in Tennessee was expected by late 1973,[56] but was delayed by the energy crisis that year.[57] On December 20, 1974, the entire final stretch between US 11E and SR 126 was dedicated by then-Governor Winfield Dunn, and partially opened, with some portions restricted to two lanes.[58][59] This stretch cost $49.4 million (equivalent to $214 million in 2021[60]), and was dedicated on the same day that the last sections of I-40 and I-75 in Tennessee were opened.[61][62] I-81 was officially completed in Tennessee on August 27, 1975, when all four lanes of the final section were fully opened to traffic.[3]

On April 6, 1997, a carjacking that culminated in the Lillelid murders occurred at the I-81 southbound rest area near Baileyton.[63] A group of six youths from Pikeville, Kentucky, forced the four members of the Lillelid family into their van and to drive approximately 3.5 miles (5.6 km) on the Interstate to the SR 172 interchange, which was the next exit.[64] The family was then taken to a secluded road nearby where they were shot. Three of the victims died, and the lone survivor was left permanently disabled.[65] The perpetrators were apprehended two days later in Douglas, Arizona, trying to flee into Mexico, and later sentenced to life in prison.[66]

Work to widen the northernmost 1.3 miles (2.1 km) of I-81 in Tennessee to six lanes, along with the southernmost 7.5 miles (12.1 km) in Virginia, began in April 1998.[67] Initially planned for completion in late 2000, the project experienced multiple delays and cost overruns, and was not completed until March 2003.[68][69] A 2008 study conducted by TDOT on the I-40 and I-81 corridors identified a number of steep grades on both Interstates difficult for trucks to ascend, causing congestion and safety hazards. This study resulted in the construction of a truck climbing lane on I-81 northbound between the Holston River and SR 357 that was completed in 2019.[70][71]

Between September 2011 and June 2014, the interchange with US 25E was modified in a project that replaced the southbound loop onramp with a traditional diamond ramp, widened the radius of the northbound loop exit ramp, replaced the US 25E overpass with a wider bridge, and added turn lanes at the intersections with the ramps. This project was necessitated by the hazardous conditions of the previous configuration and the adoption of US 25E as part of an alternate route to I-75.[72]