Publication of Anthologie de la poésie canadienne d’expression française established him as an intellectual and a specialist in Canadian poetry.
[2] Sylvestre served as a translator in the Senate of Canada 1942–1944 and at the World War II Wartime Information Board in 1944–45.
Louis St. Laurent, Prime Minister of Canada, between 1945 and 1950, a position which led to important civil service jobs.
The library experienced extraordinary growth under his leadership, housed in a new building on Wellington Street.
Ordre International du bien public, 1970; Order of Merit of the Republic of Poland ; IFLA Medal; Canadian Representative Intergovernmental Council for General Information Programs, Unesco 1979–83; Canadian Delegation to UNESCO, Conferences 1949, 1970, 1972, 1974; Chairman, Conference of Directors of National Libraries, 1974–77; Chairman, National Libraries Section, IFLA, 1977–81; Canadian Public Service Outstanding Public Service Award, 1983; Societa' Dante Alighieri, rome, 1971; Life member, Canadian Library Association,(CLA); Association Technologie de la documentation; Honorary Life member, Ontario Library Association(OLA); Member and First President, Canadian Association for Information Science; Recipient of Queen Elizabeth II Golden Jubilee Medal.