He became a plumber, and a member of St. Casimir's Civic and Athletic Association, of the American Federation of Labor, and of his local Democratic Club.
Landowski had not held any public office until his election to the Assembly's 13th Milwaukee County district (the 13th & 21st Wards of the city of Milwaukee) in 1948 to succeed fellow Democrat William Nawrocki, who was not a candidate for re-election.
[4] He was an unsuccessful candidate in 1952's spring election for the Milwaukee County board of supervisors.
[6] He was elected alderman for Milwaukee's 18th ward in April 1956 (winning by 58 votes)[7] He did not run for re-election to the Assembly, and was succeeded there by Republican John Meyer.
In 1960 Landowski sought re-election to the Milwaukee Common Council, but was ousted by insurance agent Allen Calhoun, who won by almost 1400 votes.