According to Wikipedia, "On March 3, 1876 in a 100 by 50 yard area near Olympia Springs, Bath County, Kentucky, large chunks of red meat fell from the sky for a period of a couple of minutes. The phenomenon which was referred to as the Kentucky meat shower was reported by the New York Times and several other publications at the time."
At first, "the "meat" was identified by a Mr. Leopold Brandeis writing in the Sanitarian as Nostoc, which he described as a type of vegetable matter." But then, when Brandeis "passed the meat sample to the Newark Scientific Association for further analysis, this lead to a letter from Dr. Allan McLane Hamilton appearing in the publication Medical Record stating that the meat had been identified as lung tissue from either a horse or a human infant ("the structure of the organ in these two cases being very similar.") The makeup of this sample was backed up by further analysis, with two samples of the meat being identified as lung tissue, three samples were of muscle tissue, and two of cartilage."