So, it’s somewhat surprising that our oldest (surviving) photograph of the Moon wasn’t taken until 1849.
The first photographer is widely acknowledged to be a French inventor named Joseph Nicéphore Niépcethe. He started experimenting with ways to record light in 1814. One of the oldest surviving photos of any kind was taken in 1825 when Niépce captured the black-and-white image of an engraving of a boy pulling a horse. However, this method required a full eight hours of exposure.
In 1839, another Frenchman, Louis Daguerre, invented the first commercial photographic process which he called a “daguerreotype.” He had figured out how to reduce exposure time to only 20 to 30 minutes. A highly polished silver surface on a copper plate was sensitized to light by exposing it to iodine fumes. After exposing the plate in a camera it was developed with mercury vapor. According to the American Physical Society, Daguerre had daguerreotyped a faint, imperfect image of the (crescent) Moon in 1939, but a fire destroyed his work.
In 1840, just a year later, John W. Draper of New York City is credited with making a clearer daguerreotype of the (full) Moon in March 1840, but this also was destroyed in a fire.
This brings us to 1849!
On the night of September 1, 1849, the nearly full Moon appeared over the town of Canandaigua, New York. At 10:30 P.M., Samuel D. Humphrey slid a highly polished, silver-plated copper sheet measuring 2–3/4x1–3/4 inches into his camera, which was pointed at the Moon.
Humphrey then exposed the light-sensitive plate to the shining Moon nine times, varying the length of exposure from 0.5 seconds to 2 minutes. After developing the plate with mercury vapor, he sent his daguerreotype to Harvard College.
By 1851, the Harvard College Observatory was producing detailed, world-renowned daguerreotypes of the Moon, doubtless inspired by Humphrey, whose 1849 daguerreotype is now considered by many to be the earliest extant photograph of the Moon.