He was subsequently appointed as first vice president of the Bethlehem Steel Corporation in charge of foreign sales.

Upon his retirement from Bethlehem Steel in 1927, he began describing himself as a "gentleman farmer" and continued in public service until his death at his home in 1948.

Estelle was active in the life of Bethlehem's Central Moravian Church, where she was a member of the Twenty Minute Society and Opportunity Circle.

According to her obituary, she maintained a lifetime interest in Moravian College's Helen Stadiger Borhek Chapel, given by her parents in honor of her sister, who died in childhood.

Estelle died on November 17, 1952, at the family's home, Camel's Hump Farm, in Bethlehem Township, Pennsylvania.

After receiving his bachelor's degree, Johnston returned to the Bethlehem Iron Company's physical laboratory.

By age 25, Johnston was responsible for the erection of John Fritz-designed 125-ton hammer used in the manufacture of armor plates for ships.

A 1918 book entitled "Men of Bethlehem" published by Fred L. Shankweiler describes Johnston as having "entered the employ of the Bethlehem Steel Company, physical testing department, in 1889 and later was in charge of the erection and operation of the gun forging plant, the first to be established in America.

"[5] Johnston retired from the Bethlehem Steel Corporation in 1927, and remained a member of the board of his directors until his death in 1948.

The bridge became the physical manifestation of the unification of the two boroughs and remains the primary traffic artery between the northern and southern portions of the city.

In 1958, Moravian College named its field house “Archibald Johnston Hall” in recognition of his service to the institution.

The Monocacy Creek ran north from its confluence with the Lehigh River in the then-borough of Bethlehem to multiple headwaters in the central part of the county.

The painting contract was let to Frank Mitman of West Broad Street, and brick and stucco work to Morris Brewer of Broadway.

Another branch of this road carried visitors from the boat house up a serpentine drive to the front entrance of the mansion, situated on a rise approximately 60 feet above the creek.

She left her Bethlehem Township property, consisting of 55 acres (22.3 hectares) comprising the Archibald Johnston mansion and the grounds surrounding it (noted as parcel numbers M7 7 2 0205E, which includes the majority of the property, and M7 7 2B 0205, a smaller residence parcel), to Bethlehem Township for use as a public park.

In subsequent years, a study was done by Pennoni Associates of the Housenick property gift, and in 2013 trail markers and information kiosks were erected.

On October 17, 2014, Natural Lands Trust learned that they were awarded the second of two open space grants from the Commonwealth of Pennsylvania to purchase two parcels owned by Bethlehem's Central Moravian Church.

The group, a nonprofit 501(c)(3) organization, is "committed to the preservation, restoration and sustainable adaptive reuse of the estate of the first Mayor of Bethlehem, Archibald Johnston, to meet the needs of [the] community."

The parcel is bisected by the Bethlehem-Bethlehem Township municipal border and contains a small stream running from east to west toward the Monocacy Creek.