The creation of Mount Auburn cemetery outside Boston is generally credited with beginning the "rural cemetery" movement (sometimes also and more accurately called "park cemetery" or "garden cemetery", though the former term was the one that stuck): carefully landscaped burial places that replaced their rather unkempt and desolate Colonial predecessors and served the needs of the living as much as those of the dead. It is from this prototype that most of us derive our image of a cemetery, and indeed, it was then that the term, "cemetery," began to replace "graveyard" and "burial ground."
These attractive, peaceful spaces reflected a new attitude toward death and were seen as tools of aesthetic and political education--as Nehemiah Allen put it in 1834, "a feeling of the spontaneous goodness of God." "Man should learn from Him, to be the same everywhere that he should choose to be in the sight of his fellows, and to have all his actions proceed from a deep, uncompromising conviction of duty, and love of what is right, rather than from a hope of reward." Humble monuments to ancestors and local worthies were viewed as appropriate to a republic, a constant spur to patriotic citizenship. An anonymous writer said of the Forest Hills Cemetery in Roxbury in 1855, "The spot where their fathers and friends are buried, if it possess those charms which impress the heart and gratify the taste, will never be forgotten, and the land which contains it, though it have no other attraction, will yet be dear [to the living] for this."
The rural cemeteries were so popular that they became the destination of outings. In the 1840s, when Lady Emmeline Wortley visited the President of Harvard, she recalled that the first trip was to Mount Auburn, and afterward "we went to see a little of the colleges." So popular were the new spaces, that they spurred the creation of urban parks, in part in order that the veneration of the dead and recreational activity might better be separated.
Resources: Mount Auburn Cemetery; Mass Moments entry