"The Arnold Arboretum was established in 1872 when the trustees of the will of James Arnold (1781-1868), a whaling merchant of New Bedford, Massachusetts, transferred a portion of Arnold's estate to the President and Fellows of Harvard College. The Arboretum occupies 265 acres (107 hectares) of land in the Jamaica Plain section of Boston, and is a key link in the Emerald Necklace, a 7-mile-long network of parks and parkways that civic visionary Frederick Law Olmsted laid out for the Boston Parks Department between 1878 and 1896."
Excerpted from the website: http://www.arboretum.harvard.edu/visitors/visitors.html.