The construction of PA 33 started in 1959, and stretched from the PA 512 interchange to Saylorsburg.
 Construction finished in 1960.
 The stretch connecting the highway to I-80 was built and completed by 1964.
 Construction on PA 33 was not continued until 1969 when work began on the stretch from PA 512 in Wind Gap to Henry Road in Belfast.
 This stretch was completed by 1970.
 By 1972, the road had reached what is now PA 191 in Stockertown, and was extended down to its long-term southern terminus at US 22.
 The highway was left at that until 1999 when construction began on a final segment that would connect the US 22 interchange to I-78.
The final three-mile (5 km) stretch opened in January 2002.

In January 2004, the expressway was shut down between Lower Nazareth Township (PA 248) and Stockertown (PA 191) because of a sinkhole that was in the area of the Bushkill Creek directly under a northbound bridge support beam.
 Crossovers were created, narrowing the highway to one lane in each direction through Stockertown.
 Studies were conducted, and came to the conclusion that the bridge was dangerous and could not be fixed.
 The northbound bridge was demolished in February of the same year.
 Just 21 days later, a sinkhole was discovered under the southbound bridge over the Bushkill Creek, and resulted in the demolition of the southbound bridge.
 Once the new northbound bridge was completed, another crossover was created, detouring southbound traffic onto the northbound side of the highway.
 On April 21, 2004, a depression formed under the new northbound bridge, and the highway was shut down once again to fill the area with bituminous material.
 The bridge re-opened within twenty minutes.
 By November 19, 2004, both bridges were completed and opened.
 All of this happened feet from the Bushkill Street Bridge, which connects Stockertown and Palmer Township, and has been closed since 1999 because of numerous sinkholes causing the bridge to collapse.

On March 21, 2009, a tractor-trailer carrying 32,000 pounds of hydrofluoric acid overturned on southbound PA 33 in Plainfield Township, prompting the evacuation of about 5,000 people.
The truck, registered to the Honeywell company, flipped over at about 2:40 a.m. after the driver swerved to avoid a deer.
Nobody was injured and the highway was reopened later that day.
Hundreds of evacuees were taken to the Pen Argyl Area High School in nearby Pen Argyl.

On January 31, 2013, ground was broken for a new interchange at Main Street in Palmer Township to the west of Tatamy, with Governor Tom Corbett in attendance.
This interchange is being constructed to serve the Palmer Industrial Park and is expected to bring economic development to the area.
Completion of this interchange, which is to cost $40 million, was originally planned for November 2014.
However, work on the project was halted during the winter of 2014-2015, with completion pushed back to June 2015.
The construction of PA 33 started in 1959, and stretched from the PA 512 interchange to Saylorsburg.  Construction finished in 1960.  The stretch connecting the highway to I-80 was built and completed by 1964.  Construction on PA 33 was not continued until 1969 when work began on the stretch from PA 512 in Wind Gap to Henry Road in Belfast.  This stretch was completed by 1970.  By 1972, the road had reached what is now PA 191 in Stockertown, and was extended down to its long-term southern terminus at US 22.  The highway was left at that until 1999 when construction began on a final segment that would connect the US 22 interchange to I-78. The final three-mile (5 km) stretch opened in January 2002.
In January 2004, the expressway was shut down between Lower Nazareth Township (PA 248) and Stockertown (PA 191) because of a sinkhole that was in the area of the Bushkill Creek directly under a northbound bridge support beam.  Crossovers were created, narrowing the highway to one lane in each direction through Stockertown.  Studies were conducted, and came to the conclusion that the bridge was dangerous and could not be fixed.  The northbound bridge was demolished in February of the same year.  Just 21 days later, a sinkhole was discovered under the southbound bridge over the Bushkill Creek, and resulted in the demolition of the southbound bridge.  Once the new northbound bridge was completed, another crossover was created, detouring southbound traffic onto the northbound side of the highway.  On April 21, 2004, a depression formed under the new northbound bridge, and the highway was shut down once again to fill the area with bituminous material.  The bridge re-opened within twenty minutes.  By November 19, 2004, both bridges were completed and opened.  All of this happened feet from the Bushkill Street Bridge, which connects Stockertown and Palmer Township, and has been closed since 1999 because of numerous sinkholes causing the bridge to collapse.
On March 21, 2009, a tractor-trailer carrying 32,000 pounds of hydrofluoric acid overturned on southbound PA 33 in Plainfield Township, prompting the evacuation of about 5,000 people. The truck, registered to the Honeywell company, flipped over at about 2:40 a.m. after the driver swerved to avoid a deer. Nobody was injured and the highway was reopened later that day. Hundreds of evacuees were taken to the Pen Argyl Area High School in nearby Pen Argyl.
On January 31, 2013, ground was broken for a new interchange at Main Street in Palmer Township to the west of Tatamy, with Governor Tom Corbett in attendance. This interchange is being constructed to serve the Palmer Industrial Park and is expected to bring economic development to the area. Completion of this interchange, which is to cost $40 million, was originally planned for November 2014. However, work on the project was halted during the winter of 2014-2015, with completion pushed back to June 2015.
Pennsylvania Route 33