Laurens had a horror of being buried alive, a fear sharpened by the fact it nearly happened to his daughter. As an infant, Martha Laurens was declared to have died from smallpox. Laid out for a swift burial near an open window, she suddenly stirred, perhaps because of the cool air, and was spared the fate Laurens so feared.
(Image: Martha Laurens as a small girl, 1767, by John Wollaston)
In his will Laurens directed that his body be “wrapped in twelve yards of tow cloth and burnt until it be entirely and totally consumed….” After his death at his beloved Mepkin Plantation in December 1792, his instructions were carried out. The plantation slaves built a large funeral pyre. Laurens’ body was placed upon it and set alight.
Martha, now Mrs. Ramsay, refused to witness what she called “the awful ceremony.”  Henry’s ashes were deposited in a grave next to that of his son John, who had been killed in action in 1782, near the end of the War for American Independence. 
Cremation probably appealed to Henry Laurens for another reason: it was a form of bodily disposal accorded to heroes in the classical world. It is notable that he had placed a classical inscription from the Roman poet Horace on John Laurens’ gravestone: Dulce et decorum est, pro patria mori ("It is sweet and honourable, to die for one’s country.")
Laurens’ cremation may have been the first to be recorded in the United States, but some Native American nations had long employed it. The history of cremation spans many thousands of years, numerous cultures, and every continent. The Romans used cremation extensively, especially as a dignified send off for soldiers. Christians and Jews, however, opposed cremation in favour of burial in tombs.
After Roman Emperor Constantine adopted Christianity in the early 4th century, the Church condemned cremation as a pagan practice, and it was gradually abandoned where Christianity prevailed. During epidemics and after battles, however, bodies were sometimes burned, mainly for hygienic reasons. The smell of decaying bodies was long believed to be a source of deadly infections.
Henry Laurens’ cremation did not spark a trend. Few people even knew of it at the time. Nevertheless, opposition to the practice slowly declined during the late 19th century. Part of the increased interest in cremation arose from concerns that overcrowded urban cemeteries were a source of diseases like cholera and typhoid. Part may also have arisen from the same fear that drove Laurens to it: fear of premature burial.
Cremation as we know it today dates from the Vienna Exhibition of 1873, when Professor Ludovico Brunetti displayed his new invention: an efficient cremation furnace. News of his invention and improved models spread fast. The first cremation chamber in the United States opened in Washington, Pennsylvania in 1876. Since then, cremation has gradually become common in many countries.
Quotations and details of Henry Laurens' cremation are from David Duncan Wallace, The Life of Henry Laurens (G. P. Putnam's Sons, New York, 1915, pp. 457-458)