Education
Born in Saint Louis, Missouri, Ploeser attended the public schools of Saint Louis, Missouri, Casper and Lusk, Wyoming, and the City College of Law and Finance, Saint Louis, Missouri.
Diplomat politician representative
Born in Saint Louis, Missouri, Ploeser attended the public schools of Saint Louis, Missouri, Casper and Lusk, Wyoming, and the City College of Law and Finance, Saint Louis, Missouri.
He engaged in the insurance business in Saint Louis, Missouri, in 1922 and founded his own company in 1933. Organizer and chairman of the board of Marine Underwriters Corporation 1935. He served in the State house of representatives in 1931 and 1932.
Ploeser was elected as a Republican to the Seventy-seventh and to the three succeeding Congresses (January 3, 1941 – January 3, 1949).
He served as chairman of the Select Committee on Small Business (Eightieth Congress). He was an unsuccessful candidate for reelection in 1948 to the Eighty-first Congress.
He served as delegate, 1964 and 1968 Republican National Conventions. He resumed the insurance business.
He served as director of Webster Groves Trust Company.
Ambassador to Paraguay in 1957–1959. Ambassador to Costa Rica in 1970–1972. He was a resident of Saint Louis, Missouri, until his death on November 17, 1993.