The Tricentennial ended in 1996. This site archives that history.
Prince George's County Celebrates 300
years of history 1696-1996
Horticulture in Hyattsville
Civic groups and organizations such as the Boy Scouts of America, the
League of Women Voters, and the Friends of the Libraries are found across the
nation, and Prince George's County is certainly no exception. Prince
George's County has had a diverse range of community and special interest
groups over the years, providing its residents with the opportunity to
take part in civic affairs.
The Hyattsville Horticultural Society, organized during the
winter of 1916-17, was established to bring together people interested in
horticulture and floriculture. Although the original charter members
were only men, women
were later admitted to the society. Activities sponsored by the Hyattsville
Horticultural Society included lectures, flower shows, and exhibits.
From the records of the Hyattsville Horticultural Society.
Prince George's County 
Prince
George's Tricentennial Home page.