According to Daniel H. Ludlow Alma 18:9 states that "the king had commanded his servants . . . that they should prepare his horses and chariots, and conduct him forth to the land of Nephi." Two major questions have been raised by anti-LDS critics of the Book of Mormon concerning the statement that there were "horses and chariots" on the American continents before the time of Christ (see Alma 18:9). These critics have maintained that:
(1) no horses existed on the American continents before the time of Columbus; and
(2) the people who lived on the American continents did not know the principle of the wheel before the coming of Columbus.
However, since the publication of the Book of Mormon, considerable archaeological evidence has come forth to reinforce its claims that there were horses on the American continents before the time of Columbus and that these early peoples did know the principles of the wheel. [Daniel H. Ludlow, A Companion to Your Study of the Book of Mormon, p. 206]
According to Hunter and Ferguson, the claim made by the Book of Mormon that horses were on this continent and used in ancient America for purposes similar to the uses we make of them today finds strong support in the numerous fossil remains of horses that have been obtained from the asphalt deposits of Rancho La Brea in southern California. Of course, it is claimed that those fossil remains pre-date Book of Mormon times. However, there is no logical reason for believing, since horses were here prior to the arrival of the Jaredites and the Nephites, that horses could not have still been in America during the period in which those ancient civilizations flourished. . . . We could do no better at this point in dealing with this subject than to quote from an official publication of the Los Angeles County Museum on the subject of the existence of horses in early times in America:
The presence of herds of horses in the vicinity of the asphalt deposits during the period of accumulation is clearly testified to by the numerous remains of these mammals found at Rancho La Brea. While many individuals are recorded in the collections, all of them belong to a single species, the extinct western horse (Equus occidentalis Leidy). In stage of evolution and in general body structure this type resembles the modern horse, although differing from it in a number of specific details. Standing on the average about 14 1/2 hands (4 feet, 10 inches) at the withers, this animal was of the height of a modern Arab horse. It was, however, of considerably heavier build . . .
Horses were among the more common types of hoofed mammals on the North American continent during Pleistocene time and several distinct species have been described from fossil remains. The abundance and widespread distribution of horses in North America make the apparent disappearance of the group in this region prior to the advent of the white man an added and an unusual feature of their long and eventful career.[Milton R. Hunter and Thomas Stuart Ferguson, Ancient America and The Book of Mormon, pp. 312-313]
Joy Osborn provides the following interesting quote relative to horses in the Americas:
Fossil remains of true horses, differing but very slightly from the smaller and inferior breeds of those now existing, are found abundantly in deposits of the most recent geological age, in almost every part of America, from Escholz Bay in the north to Patagonia in the south. In that continent however, they became quite extinct, and no horses, either wild or domesticated, existed there at the time of the Spanish conquest, which is the most remarkable as, when introduced from Europe the horses that ran wild proved by their rapid multiplication in the plains of South America and Texas that the climate, food, and other circumstances were highly favorable for their existence. The former great abundance of Equidae in America, their complete extinction, and their perfect acclimatization when reintroduced by man, form curious but as yet unsolved problems in geographical distribution. (New Americanized Encyclopedia, Vol. 5, p. 3197)[Joy M. Osborn, The Book of Mormon -- The Stick of Joseph, p. 159]