Today's US 401 was not commissioned until 1957.  There was a different US 401 in 1933.  But this page discusses the first US 401.  Claim to fame: US 401 was the first US route to be commissioned after the initial list of US routes was approved in November 1926.  It appeared on the April 1927 route log:
Other new routes also showed up on that log: US 9E, US 9W, US 30N, and US 41W.  But those were all bannered routes; US 401 was the first mainline US route after 1926.  US 401 was not commissioned with the original US routes in Nov. 1926, because there was no need for it.  Maps showed US 15 heading north to Clarksville, but then turning east and terminating in South Hill at its junction with US 1. 
However an AASHO route log from April 1927 (just five months later) indicated that US 15 had been changed to continue north from Clarksville, and that its originally-planned route between Clarksville and South Hill had been designated US 401.  Here is that portion of the first Virginia official state highway map to indicate the change:
Picture
c. 1929, VDoT
At the time, US 1 came into South Hill from the north via Mecklenburg Avenue, and then turned west on Danville Street (as it does yet today).  But instead of staying on Danville, US 1 was directed south on Goodes Ferry Road, and it then followed today's VA hwy. 903 out of town.  From that turn US 401 began by continuing west on Danville, then splitting off to Plank Road.  This photo was taken looking the opposite direction (east on Danville).  The blue car was at the north end of Goodes Ferry Rd (original US 1).  In the late 1920s and early 1930s, if a driver there wanted to continue north on US 1, he would turn to his right (away from the camera).  But if he turned toward the camera, he would have been at the east beginning of US 401:
Picture
Karners, Dec. 2016
During the short time it existed, the routings of both US 1 and US 401 were changed in the South Hill area.  As a result, there were three different places where US 401 junctioned US 1.  Initially the junction was right in South Hill, at the intersection shown above.  By 1927, US 1 had been rerouted to its current alignment, so US 401 met US 1 at Lombardy Grove (about five miles south of South Hill).  Then in 1930, US 401 was realigned to follow the current path of US 58, so it met US 1 about six miles south of South Hill.  However, the route logs suggest that US 401 never ended at those later junctions with US 1... rather, it was always overlapped to its original endpoint in South Hill (more info on VAHighways.com).
At first the west end of US 401 was at US 15 in Clarksville.  Obviously this junction has changed significantly since the late 1920s, but it represents where US 401 ended at US 15 for a few years:
Picture
Elkins, July 2008
Then in about 1930, the route was extended west, to the junction with US 501 in South Boston.  ​Virginia's map from the same year was the first to indicate this extension:
Picture
c. 1930, VDoT
This photo was looking north on US 501.  It is possible that US 401 began to the right on today's US 58-360...
Picture
Storey, Nov. 2002
...but that extension may have never been signposted, because it was less than a year later that US 58 was commissioned.  What had been US 401 then became a small segment of the new US 58 (that was illustrated on Virginia's map issued in 1932).
Research and/or photo credits: H.B. Elkins; Karin and Martin Karner; Mike Roberson; Dale Sanderson; Jimmy Storey; Michael Summa
Page originally created 2003;
last updated Mar. 13, 2022.