In Colonial times, this area known as Back Bay was literally that: an inland bay alongside the peninsula on which Boston was established. Twice a day the Atlantic tides would send cleansing waves up the Charles River to flood it. That is, until the 1820s, when an enterprising mill company built a dam along what is now Beacon Street.
Some 50 years later, the state finished the job with landfill. Commonwealth Avenue Mall became the spine of the elegant new Back Bay neighborhood and the crucial green link between the Public Garden and Frederick Law Olmsted's park system.
The Mall's 32 acres were designed in the French boulevard style by Arthur Gilman in 1856. Frederick Law Olmsted and Charles Sprague Sargent, partners in creating the Arnold Arboretum, were asked in 1880 for advice on tree planting patterns. Their suggestion was "to obtain . . . the uniformity which seems to us essential to the future beauty and dignity of the finest street in the city." removing the trees already planted and replacing them with two single rows of European elms. Fearing public outcry at losing existing trees, the City Council rejected the proposal. Still, the Mall was known for magnificent American elms, some of which survive the Dutch Elm disease that devastated the species in recent decades.
Today, sweetgum, green ash, maple, linden, zelkova, Japanese pagoda and elm define this formal avenue, along with monuments decorating its expansive central promenade.
The Friends of the Public Garden and Common is a non-profit citizen's advocacy group formed in 1970 to preserve and enhance the Boston Public Garden, Common, and Commonwealth Avenue Mall in collaboration with the Mayor and the Parks Department of the City of Boston. The Friends number over 2500 members and many volunteers. The Friends have also produced a brochure detailing the park's history.
More Information on Friends of the Public Garden