> One of the reasons why eating in cemeteries become a “fad,” as some reporters called it, was that epidemics were raging across the country: Yellow fever and cholera flourished, children passed away before turning 10, women died during childbirth. Death was a constant visitor for many families, and in cemeteries, people could “talk” and break bread with family and friends, both living and deceased.

It's fascinating that the article also notes that the older generation at the time (late 19th century) viewed the fad with disgust:

> But plenty of Americans believed that picnics in local cemeteries were a “gruesome festivity.” This critique, notably from older generations, didn’t stop young adults from meeting up in graveyards. Instead it led to debate over proper conduct.

This was a phenomenon driven by the times. Lots of deaths mean you spend a lot more time at the cemetery. Cemeteries started to lose their association with loss/decay and gained more of an association with remembrance.

There's quite a lot on this topic, like this article, which notes that another reason for the pull of cemeteries at that time was the Civil War:

> ... Beginning in the late 1800s, cemeteries were prime picnic spots. Remember, in the aftermath of the bloody Civil War and in an age of cholera and yellow fever, cities created large new cemeteries to accommodate the dead. Family farms or sacred churchyards were no longer the only spots for burial grounds. These new-age cemeteries looked and functioned more like public parks than stark, spooky graveyards. They featured professional landscaping, winding paths, ponds, and pavilions.

https://connectingdirectors.com/55122-cemetery-picnics