According to John Sorenson, the great amount of interrelated information presented in this portion of the scripture [Alma 50--51] enables us to relate the record to the Nephite physical scene. All the places mentioned can be identified with plausible geographical scenes and archaeological sites. The reasons for settlement in those spots become apparent, and the logic of Amalickiah's campaign and of Moroni's defense are clarified.
A line marking the limit of Mayan languages and culture runs through this east central area. This border apparently held at the time of the Spanish conquest, just as it had many centuries earlier in Classic times. Even in ancient Olmec days, sites of that culture fell on one side of this line. It seems that some sort of ecological boundary must separate the territory on either side of the line, inhibiting flows of population and culture across it. Whatever the cause, a narrow zone twenty or so miles wide does seem to have constituted a long-lasting ethnic frontier. The zone falls precisely where the Nephite-Lamanite boundary ["a straight course from the east sea to the west"--Alma 50:8] in the east sea sector fits in the geography.
The geographical area of southern Mexico where the Nephite defenders stood against the Lamanites is now called the Chontalpa. Sluggish stream drainage leaves much of the flat land too wet to settle, but here and there higher spots on river levees or slight geological rises permit villages to exist. . . . Travel through the coastal area is limited to two or three well-established trails that run roughly northwest-southeast along the higher ground. Native warfare at the time of the Spanish Conquest was confined mostly to October through February. Food was then abundant, and the seasonal flooding had mostly abated. Along the coast lies a strip of overgrown old beach dunes up to a couple of miles wide. It is continuous enough to permit travel along it parallel to the beach and free from the swamps just inland, which hold the discomforts of sand, wind and insects.
The Chontalpa zone is bounded on one side by the Rio Seco. Until colonial Spanish times, the main stream of the Grijalva River reached the sea via the channel of the Seco, but then the high-leveed stream in one of its regular floods broke into a new outlet far to the east, where it now runs. The old course essentially followed the language and culture boundary mentioned above. As R. Gadacz notes, "Many of the rivers in Tabasco served as provincial boundaries." The river is a formidable enough barrier that it would have made a logical defense line for captain Moroni. The city of Moroni and the city of Nephihah were the key garrisons anchoring this neat "line of the possession of the Lamanites" (Alma 50:13). This geographical picture explains why the Nephite record never mentions the Sidon river on the east coast, because the stream itself constituted the frontier rather than being a feature that the Nephites had need to cross. [John L. Sorenson, An Ancient American Setting for the Book of Mormon, pp. 245-246]
Alma 50:8 The land of Nephi did run in a straight course from the east sea to the west (Illustration): John Sorenson's Nephite region and boundary which could be defined as a "straight course from the east sea to the west" (the Chontalpa zone bounded on the one side by the Rio Seco). Archaeological Map of Middle America: Land of the Feathered Serpent. Produced by the Cartographic Division , National Geographic Society, 1972.
Alma 50:8 The land of Nephi did run in a straight course ([Illustration]): The Mixe-Zoque/Maya Interaction Zone -- Map showing distribution of major culture areas in Mesoamerica as related to Izapa and a highly idealized zone of Mixe-Zoque/Maya interaction; in Preclassic times the zone of interaction may have curved closer to the Usumacinta River and its tributaries [Gareth W. Lowe, Thomas Lee, Jr, and Eduardo Martinez, Izapa: An Introduction to the Ruins and Monuments, p. 306]
Alma 50:8 And the land of Nephi did run in a straight course from the east sea to the west ([Illustration]): Map 14. The boundary of the Land Nephi did run in a straight course from the east sea to the west. [Jerry L. Ainsworth, The Lives and Travels of Mormon and Moroni, p. 97]
“A Straight Course from the East Sea to the West”
The reader should note that in Alma 50:8, it does not say that the land of Nephi ran in "a straight course" from the east sea all the way to the west sea, although it might be generally comprehended that way in the reader's mind. In Alma 22:27 we find that the narrow strip of wilderness which separated the general land of Nephi and the general land of Zarahemla "ran from the sea east even to the sea west and round about on the borders of the seashore and the borders of the wilderness." What one has to define here is the meaning and ramifications of the word "straight."
According to Daniel McKinlay and John Welch, going back to the 1829 manuscripts of the Book of Mormon, one finds that the word strait appears over twenty times in the Printer's Manuscript, but the spelling "straight" was never used there. When Joseph Smith said the word strai[gh]t, Oliver Cowdery apparently always preferred to spell it "s-t-r-a-i-t." The only known instance when Oliver Cowdery spelled the word s-t-r-a-i-g-h-t on the Original Manuscript was in Alma 50:8 ("the land of Nephi did run in a strai[gh]t course from the east sea to the west"), but even there he changed it to s-t-r-a-i-t when he copied it over for the printer. Oliver's spelling is understandable, since the dictionaries of the early nineteenth century, such as Webster's 1828 American Dictionary of the English Language, show both spellings as being somewhat interchangeable. [Daniel McKinlay and John W. Welch, "Getting Things Strai[gh]t," in Reexploring the Book of Mormon, pp. 260-261]
In order to add to our understanding of the ramifications of the term "straight course," we need to gain some geographical perspective. During the preaching of the sons of Mosiah, Aaron left his brethren and was "led by the spirit to the land of Nephi, even to the house of the king which was over all the land" (Alma 22:1). Aaron preached to the king and by means of miraculous events the king was converted. The king then desired Aaron to preach to all his people, but he knew that the people would be greatly antagonistic towards Aaron and his brethren; therefore, he sent a proclamation to all his people granting safety to Aaron and those who preached with him. Mormon geographically embellished the incident as follows:
And it came to pass that the (Lamanite) king sent a proclamation throughout all the land, amongst all his people who were in all his land, who were in all the regions round about, which was bordering even to the sea, on the east and on the west and which was divided from the land of Zarahemla by a narrow strip of wilderness, which ran from the sea east even to the sea west, and round about on the borders of the seashore, and the borders of the wilderness which was on the north by the land of Zarahemla, through the borders of Manti, by the head of the river Sidon, running from the east towards the west--and thus were the Lamanites and Nephites divided.
Now, the more idle part of the Lamanites lived in the wilderness, and dwelt in tents; and they were spread through the wilderness on the west, in the land of Nephi; yea, and also on the west of the land of Zarahemla, in the borders by the seashore, and on the west in the land of Nephi, in the place of their fathers' first inheritance, and thus bordering along by the seashore.
And also there were many Lamanites on the east by the seashore, whither the Nephites had driven them. And thus the Nephites were nearly surrounded by the Lamanites; nevertheless, the Nephites had taken possession of all the northern parts of the land bordering on the wilderness, at the head of the river Sidon, from the east to the west, round about on the wilderness side; on the north, even until they came to the land which they called Bountiful. (Alma 22:27-29, italics added)
Here in these verses, Mormon makes us aware that there were Lamanites living not only on the west of the land of Nephi and on the west of the land of Zarahemla, but "on the east by the seashore." The question we can then ask is, On the east of what land? the land of Zarahemla? the land of Nephi? or both? Mormon answers that question by saying, "And thus the Nephites were nearly surrounded by the Lamanites." In other words, in order for the Nephites to be "nearly surrounded by Lamanites," there had to be Lamanites living on the east of the land of Zarahemla in addition to those living on the east of the land of Nephi. Despite the fact that in verse 27 Mormon states that the Lamanite lands were separated from the general land of Zarahemla "by a narrow strip of wilderness, which ran from the sea east even to the sea west," the Nephites couldn't have been "nearly surrounded" if at this time there was a straight, unyielding southern border from sea to sea. This "narrow strip of wilderness" must have had some curvature to it. Mormon makes this point clear by stating in verse 27 that this "narrow strip of wilderness" ran "round about on the borders of the seashore." Mormon also states that the more idle part of the Lamanites lived in the wilderness "on the west of the land of Zarahemla," as well as on the east (of the land of Zarahemla) "in the borders by the seashore." Thus, "idle" Lamanites wrapped around the land of Zarahemla both on the west coast and on the east coast.
In Alma 50:11, Mormon informs us that the Lamanites had "strongholds" in the east wilderness, an area Mormon had already described in Alma 22:29 as being the wilderness "on the east (of the land of Zarahemla) and being inhabited by "the more idle part" of the Lamanites. In fortifying the land of Zarahemla, Moroni drove all these "idle" Lamanites out of the east wilderness, apparently southward, so that the Nephites came to possess all the land in the east wilderness north of a "straight course." Mormon makes it clear that the southern boundary of the general land of Zarahemla had changed on the east and on the west, at least in a practical way if not an official way, to the advantage of the Nephites. Instead of going "round about" it now ran in a "straight course," thereby preventing the Nephites from being "nearly surrounded" by Lamanites. [Alan C. Miner, Personal Notes] [See Geographical Theory Maps]
Geographical [Theory Map]: Alma 50:8 Land of Nephi Runs a Straight Course (20th Year)