Gaston Co.: Gastonia (Franklin Blvd); Belmont (Wilkinson Blvd). 

Mecklenburg Co.: Charlotte (several streets, see route description; Charlotte Panthers Stadium, Charlotte Motor Speedway. 

Cabarrus Co.: Kannapolis

Rowan Co.:China Grove; Salisbury (Main St)

Davidson Co.: Lexington

Guilford Co.: High Point; Greensboro (Henry Blvd)

Rockingham Co.:Reidville (29 business on Freeway Dr)

In 1932, US 29 was extended well north, all the way to Culpeper, Virginia. It's routing through North Carolina was thus: multiplexed with US 74/NC 20 northeast via Cleveland St. (now NC 161) to Bessemer City, then east on Virginia Ave and E. 7th St (both now NC 274) to Gastonia

US 29 then folllowed Franklin Blvd. to Charlotte. US 29's first Charlotte routing used Wilkinson Blvd to W. Morehead to Mint St, then Trade St, then Tryon St, which US 29 used to head northeast out of Charlotte.

Leaving Charlotte US 29 followed NC 15 (but replaced US 170) northeast to Newell ("Old Concord Rd" today), and Harrisburg before veering off today's NC 49 on Old Charlotte Hwy to Concord via Cabarrus Ave and Church St (today's US 601 Bus), then north to Kannapolis-Landis-China Grove (all via Main St) and Salisbury, where NC 15 ended. US 29 was then routed along US 70/NC 10 northeast to Lexington (via today's Salisbury Rd), Thomasville (via Atlantic Rd) along Main St, and via Turner St, and today's NC 68 towards High Point, where US 29 used English St, then Main St (was multiplexed with US 311/NC 77) then left town on Montlieu Ave.
US 29 continued northeast to Jamestown (Greensboro Rd and Main St), Sedgefield (High Point Rd) and into Greensboro, where US 29 used High Point Rd to Lee St (current NC 6) to Fairground Ave, then Spring Garden St. to Aycock St to West Market St. to Greene St., and finally to Summit Ave, where US 29 (now paired with NC 70) headed northeast to Browns Summit, then Old Reidsville Rd to today's US 29 Bus.

US 29's original route through Reidsville utilized Scales St to Madison St back to today's US 29 Bus, then north to Ruffin, then along Mayflower Rd and "Old US 29" to Pelham and Shelton before heading into Virginia about where the current railroad crosses the stae line.  

The first change to US 29 came in 1933, when it was rerouted to avoid Browns Summit (using the northernmost reach of Summit Ave), leaving behind today's Browns Summit and part of today's NC 150. 

In late 1934, US 29 dropped its state route multiplexes: all of NC 205 (SC to Kings Mountain), NC 20 (Kings Mountain to Charlotte), NC 15 (Charlotte to Salisbury), NC 10 (Salisbury to Greensboro), and NC 70 (Greensboro to VA). 

In 1937 or 1938, US 29 underwent two changes: First, US 29 was given the direct alignment between Kings Mountain and Gastonia, replacing a piece of today's NC 7. The old way through Bessemer City became US 29A-74A. Today this is served by NC 161 and NC 274.
Second, US 29 was given a newly constructed bypass of Kannapolis, Landis, and China Grove. The old route through these places became US 29A (which it remained until a few years ago - today this is currently not a primary route)  

By 1939, (definitely after 1936), US 29 changed its Charlotte street routing. Instead of Mint St, US 29 (with US 21) used Graham St. Then US 29 cut east on 11th St to Tryon. Only Trade St. remained part of the primary route system at that time (as NC 16) from US 29's original path from Morehead St. to Tryon St. 

In 1940 or 1941,, US 29 was placed back on the route through Kannapolis, Landis, and China Grove, replacing US 29-A. The bypass route then itself was renumbered as US 29-A.
Additionally, by 1941 US 29 was 4-laned from Gastonia to Charlotte.
 

Between 1943-46, US 29 underwent another minor Charlotte adjustment, using Dalton Ave to move between Graham and Tryon.
Also by 1946, more of US 29 was 4-laned: Charlotte to the US 29-29A split; China Grove to Salisbury 

Between 1947-50, US 29 was moved onto its current routing by today's Charlotte Motor Speedway, replacing what had been US 29-A for a few years first. The old route through Newell and Harrisburg to Concord became US 29-A as well as NC 49. 

In 1951 or 1952, US 29 was bypassed as new construction around Lexington and 8 miles north US 29 got another newly constructed bypass of Thomasville. In both cases the old routes through the towns became US 29-A's.
It appears that in this timeframe US 29 was routed to avoid Monticello (near Browns Summit) leaving behind "Old Reidsville Rd"
Also, by 1952, US 29 was 4-laned from Gastonia to Concord and from China Grove to near High Point. . 

In 1955 or 1956, US 29-70 received a bypass of High Point, Jamestown, and Greensboro. This new route follows the same route as US 29 today. The old route through these cities became US 29-A, which remained until the early '90s. 

In 1957 or 1958, US 29 received a newly constructed bypass of Kings Mountain, with the old route into town becoming an extended NC 216 (as it is today).
Also, US 29 received a bypass of Charlotte over new 4-lane highway. The 1958 Official Map shows the city route as de-numbered, but 1961 Rand McNally and 1961 General Drafting show a US 29 Business. The new bypass follows today's I-85 north of town and used today's US 29-NC 49 connector to get back to the older route.

Also, US 29 received a new limited access bypass of Reidsville. The old route through town would likely have been US 29-A (there are NO business designations on ANY map of North Carolina until 1960). The old route through town here is unnumbered today.
Also, US 29 received a new limited access bypass of Salisbury (along today's I-85). The old route remained part of US 601 up to Salisbury, and part of NC 150 north of town. Today the old route is again part of US 29.
The 1958 Official Map shows only about 55 miles of US 29 that are NOT 4-laned.
 

By 1963, US 29 was returned to its 1946-1958 city routing through Charlotte, leaving just I-85 to man the bypass. From China Grove to Greensboro though, US 29 and I-85 were the same road, as 85 was put on the older four-lane routings around Lexington, Thomasville, and High Point.
The 1963 Official Map shows only 27 miles of US 29 NOT 4-laned. 

Between 1964-66, US 29 was removed from I-85 in the Salisbury area, returning to its historic routing through Salisbury.. 

In the early 70's, US 29 was rebuilt as a freeway bypass east of Reidsville, extending all the way to Ruffin. The old route to Reidville, included what had been the US 29 Bypass from 1958, and Ruffin became a long US 29 Business. 

In 1982, the US 29 freeway was extended north to Pelham. Ruffin to Pelham became "Old US 29". 

In 1987 or 1988, US 29's freeway was extended north to Virginia. It is likely these northern freeway extensions were an improvement to a Super-2. 

In the 1990's, US 29 was rerouted to avoid the Charlotte Panthers Stadium. The current US 29 hugs the boundary of the stadium in following the route it has used since 1963.. 

US 29 in Virginia is known as the Seminole Trail. Oddly, the 1952 Shell Map shows US 29-74 east of Kings Mtn as the Seminole Trail, but this name appears nowhere else on the map....
US 29 is now the step-child for I-85 for most of its existence, but is still nearly all 4-lane. US 29 north of Greensboro is slated to be part of the coming I-785. Improvements to the semi-freeway between I-85 Business and NC 150 have been ongoing for a couple years now to facilitate that designation.
A ggod example of early NC interstate configurations still exist on US 29 in places between Lexington and High Point