Until 1960, the route was much different in South Greensburg.  Prior to that year, the route was signed on Broad Street and Fairview Avenue to join US 119 sixth-tenths of a mile south of where it now joins.  In 1960, the route was signed on its current alignment of Broad Street and Harvey Avenue.

Resigned in 1964 to replace PA 376 from Three Springs to Mill Creek.  In 1973, the southern terminus was moved from PA 994 in Three Springs to its current location.

In 1940, the section from Hazen to Murray Road was paved.

The western terminus was in Richardsville at PA 968 until 1984 when it was moved to PA 28 in Hazen.  In 1986, the western terminus was moved to end at US 322, replacing PA 310 from that route to Allens Mills.

Construction began on a new access route to the DuBois Regional Airport from Interstate 80 on September 22, 2005.  When it was completed on July 13, 2007, PA 830 was signed onto it and its western terminus moved from US 322 to I-80.

A median was installed in 1958 near the Rankin Bridge, by placing northbound traffic on an unimpeded bypass of the bridge.  However, the southbound still has to negotiate a signal.

A median was installed from Kennywood Park to the Rankin Bridge in 1963.  The new four-lane divided section between Viola Avenue and Second Avenue opened in 1965 in Duquesne.  Prior to that, the route turned from Duquesne Boulevard onto Viola and Second Avenues.  In 1967, the interchange with PA 885 at the southern end of the Glenwood Bridge was completed.

In October 2012, Superstorm Sandy devastated the Eastern Seaboard, and even PA 837 was not immune from the storm.  The route was closed late on October 30, 2012 and then again when part was blocked by a smaller side in West Mifflin around 4 AM the following morning.  A motorists who was driving along the highway accidentally hit the slide with his truck, which popped up into the air and blew a tire.  The driver was not hurt and crews cleared the highway by 9 AM on October 31.

Another large rock slide took place on March 7, 2023 in Allegheny County, and "large" is an understatement because what also came crashing down onto the roadway was a gigantic boulder.  Miraculously, no one was killed or even injured when it fell.  The route was closed between Saint Clair Avenue in Clairton and the Elizabeth Bridge in Jefferson Hills.  Jefferson Hills Police Department said they were dispatched to the area around 1:20 PM after two drivers had their cars damaged from driving over smaller rocks and boulders.  "Little rocks, maybe softball size, football size, but nothing bigger than that…they did not see the need to call PennDOT yesterday for that minor roadway debris.  There were no other cars after that incident that it affected.  Yes, a large boulder fell down later on in the morning but you know that’s an Act of God," Jefferson Hills Police Chief Ronald Dziezgowski said.  The chief added that his officers and the fire department closed the road for about 20 minutes to clear the rocks but did not alert PennDOT.

"It does help us especially if it impacts the roadway.  If they can report it to us, even if it's cleaned up, so our crews know that there was an incident because we had no reports of an incident earlier in the morning," PennDOT District 11 Assistant District Executive of Maintenance, Lori Musto said.  Due to the size of the boulder, the Department of Transportation couldn't use their own equipment.  "One of our emergency contractors they were able to come out with a hoe ram and break it down into smaller pieces and we are loading it in our trucks and removing it…there is damage to the road.  Just how much damage to the road at this point, we are not positive until we get the debris removed," Musto said.  Geotechnical engineers took a look at the hillside, but found no loose material and believe this to be an isolated incident.  Workers managed to clear the boulder and other debris, cleaned out the "drop zone" along the route of other debris, as well as repaired the road surface.  Musto said that crews would continue to monitor the hillside, but in the meantime, PA 837 between Clairton and Jefferson Hills reopened to traffic two days later.

The 1940s saw a lot of upgrading take place along the route starting in 1940 when the section from Beautiful Lookout Road to South Bethlehem was paved.  A year later,  the section from Windy Wiz Road to McWilliams was paved and finally in 1949, the section from Mahoning Creek to McGregor was paved.  In 1984, the northern terminus was moved from PA 68 in Reidsburg via SR 2003 to its current location.

Resigned in 1964 on its current alignment.

Until 1936, the route was signed on the current PA 358 alignment between Greenville and Sandy Lake.  In that year, it got moved to its current location.

Resigned in 1961 in its current location.

In 1936, the eastern terminus was moved from Newport to Juniata Bridge.  Also in that year, the section from Pine Grove Road to the Wheatfield Township line was improved.  In 1938, the section from Pine Grove  Road to Pennells Church Road was paved.

The eastern terminus was moved to its current location in 1960 when the US 11/US 15 expressway was completed.