[3][4] He entered the public service as a Deputy Sheriff for four years followed by work in the city treasury office in the 1870s.

His great-grandfather was one of the organizers of the German Lutheran at the corner of Smithfield Street and Sixth Avenue.

[6] During his two years as mayor, Diehl oversaw a city growing to its full commercial and industrial potential.

The ritzy and exclusive business forum Duquesne Club was founded in the city, as well as the amalgamation of Andrew Carnegie's vast industrial empire into U.S. Steel was completed.

Mayor Diehl's administration successfully completed the rudimentary expressway Bigelow Boulevard to the east neighborhoods of the city.