Frankie first appears in Washington in 1947, the year after his time in the service ended.  That year, he was hired by the city, along with Oscar Callendar, to paint bus loading zones on the square.  At the time, he was a student at Bradley University.  He got involved with the American Legion, and from the start was charged with putting on the city's Fall Festival.

By 1948, Johnston had been elevated to the 2nd Vice Commander of the Legion.

In 1949, he was named as the Vice Commander of the Legion, in the year that the organization purchased its current property on what is now Legion Road.

In 1951, Johnston was elected to the city council, elected as Commander of the American Legion, and held a board position in the Washington Jaycees.  He was becoming one of the critical men of Washington.

1952 and 1953 saw some interesting changes for Johnston as he was the owner of the original A&W root beer stand in Washington, which was located just west of what is now Gospelife Church.

By 1954, Frankie was working for the Washington Oil Company on the east end of town, and during his time at the business, they constructed the building that still stands at the 811 Walnut location today.  This year, he was again elected to the Commander position at the American Legion.  Towards the end of 1954, Johnston would branch out on his own and start Frankie's Sales & Service automobile business at 501 Walnut Street.

By 1955, Johnston was serving on the board of the Washington Recreation Association.  At this time, he was working as a Sara Lee distributor.

In 1956 Johnston was elected to his first post with the Washington Fire Department when he was named First Assistant Fire Chief.

Big changes occurred in 1958, as the Ra Mar cafe at the present site of the Washington Family Restaurant came up for sale by the original owner, Raymond Leach.  Frankie purchased the cafe and owned it for a short time.

More big changes for Johnston in 1959, as he was elected Washington's Fire Chief for a two-year term, and he was also a charter member of Washington's Association of Commerce. This group evolved into today's Chamber of Commerce.

In 1961, towards the tail end of his run as a city councilman, Frankie helped initiate the Washingtonian Award.  Johnston was instrumental in the appearance of then Illinois Governor Otto Kerner Jr. at the first Washingtonian banquet honoring Glenn Harkins.

In 1962, the influential Johnston was part of a group of Washingtonians that traveled to Springfield to lobby for the advancement of the Washington bypass.  Also in that year, he was appointed administrative assistant to the Illinois Veterans' Commission.

From 1970-1972, Frankie was the owner of Marshall's on the square.  During this time, he was a central cog in the city's Booster Days festival.

During the city's 1975 sesquicentennial celebration, Johnston served as co-chair of the committee that provided such a wonderful experience for the town's residents.

Later in his career, Frankie had two unsuccessful bids for office.  In 1977, he made his final bid for an alderman position, and in 1989, he made his first attempt at running for mayor.  Johnston would lose that election to Don Gronewald.

In the 1980s and 1990s, Johnston remained active, coordinating the Memorial Day services for the city, maintaining an officer position in the American Legion, and serving on the Rescue Squad Board as well as the Tazewell County Board.