(Last updated 4/6/2022)
Of the "main" US highways (i.e. the one- and two-digit routes), the longest nine were all east-west routes (6, 20, 50, 30, 40, 60, 70, 80, 12). And if we take the longest 16 highways, only one of them is a north-south route (US 1, shown in red here):
That stands to reason, because the United States is roughly twice as wide from east to west as it is from north to south. So it makes sense that there would be more long east-west routes.
From humble beginnings to great lengths
US 83 was among the inaugural routes of 1926. But at the time, and for the next couple years, it was a very short route -- only about 170 miles long -- running between the capital cities of the two Dakotas:
However, by the early 1930s the US 83 designation had been extended not only north to the Canada border, but all the way down to the Mexico border too. This increased US 83's distance to nearly 1900 miles, and made it one of the longest north-south US routes. Additionally, as a result of US 83's new role as a trunk route, three newer US routes were numbered as branches of US 83. Two of these soon became quite lengthy themselves, and they still exist (US 183 and US 283). Just as these highways intertwine with each other, their history is also interrelated. This article examines the evolution of US 83, as well as the x83 routes that are part of its "family".