"On the 28th of July, the line then approaching the 10th mile, and learning that the waters of the inundation were retired within the banks of the Mississippi, so that the lands were become sufficiently dry to give firm footing to the labourers, the astronomer for his Catholic Majesty taking upon himself the extending of the line through the river low ground to the eastern margin of the Mississippi. The party allotted for this service did accordingly encamp at the point D, pushing the line forward. Judging the present a convenient position for verifying the direction of the line, the astronomer for His Catholic Majesty established his observatory near the point D, and made ____observations with the circular instrument placed in the direction of the tangent____.
"The line being extended to the margin of the Mississippi on the 17th of August, the measurement from the point D, was found to be 2 miles and 180 perches English measure, (or 2111.42 French toises.) At the distance of 1 and 2 miles at the points X and Y, were erected square posts surrounded by mounds of earth, and at a distance of 88 French feet from the margin of the river, and in the parallel of latitude was erected a square post 10 feet high surrounded by a mound of eight feet in height. On this post is inscribed on the south side a crown with the letter R underneath; on the north U. S., and the west fronting on the river, Agosto 18th, 1798. Lat. 31° N. In erecting the mile post, due regard was paid to the quantity of the offsets."
Their second camp was at Little Bayou Sara. Thence on their progress at first was slow on account of the cane, twenty to thirty-five feet high, matted with vines, and the many short, steep hills, besides the rainy weather. They hardly averaged a quarter of a mile per day. The Choctaw Indians, through whose country they passed, never disturbed the party, however, therein contrasting with the Creeks beyond Mobile River the next year.
While on Little Bayou Sara they learned of the formation of Mississippi Territory and the appointment of Winthrop Sargent as governor.[150] The new governor arrived in Natchez August 6th, and General Wilkinson on the 26th, but Sargent's health did not permit him to organize the government until the next month.
But Ellicott was now outside civil complications. He made new encampments on the line at Big Bayou Sara (whence Dunbar returned to his home near Natchez,) Thompson's Creek, Darling's Creek and Pearl or Half Way River. At Thompson's the observations covered the satellites of Jupiter by night, and the sun by day. After leaving Thompson's Creek they had much trouble crossing swamps and rafting over deep streams. Those named on his map are Comite, Beaver Creek, Amite, Ticfaw, Tanchipahoe, and Boguechitoe, all easily recognized. The soil generally was poor, covered with pines on the sandy uplands. He naively tells us that while at Darling's a confidential letter from the Spanish governor-general to a Spanish officer "fell into my hands for a few hours." What right he had to open and read official correspondence between officials of a power with whom his country was at peace does not appear, but espionage went so far at this period that an American commandant at Natchez had tried to intercept Ellicott's own letters. Evidently Ellicott thought the end justified his own means. For he discovered that improper correspondence had been carried on between Spanish officials and "some gentlemen in the western part of the Union," and that nearly $20,000 had been shipped from New Orleans in that connection. Ellicott copied the "interesting parts" and dispatched them to the Department of State. This may account for Wilkinson's hostility.
November 17-19 was occupied cutting a road through the cane brake, building rafts and ferrying across Pearl River. Here they had trouble getting provisions. Supplies and the large sector had arrived by water at a bluff at the mouth of the river, but the boat could not pass two natural rafts that blocked up the stream, as they often did. Gillespie succeeded in cutting through, but provisions meantime ran out except beef. Fortunately a small supply was secured by pack-horse from Thompson's Creek, and after two weeks Gillespie came back from New Orleans, bringing a few barrels of flour. After arranging for Gillespie to correct back to Thompson's Creek, and Daniel Burnet to carry the guide line on to the Mobile, Ellicott himself went down the river, and thence through the Rigolets to New Orleans, where he arrived January 4, 1799. There he obtained supplies, conferred with Gayoso, and took observations with his six feet sector.
Meantime the guide line was plodding eastwardly through the forests. At 117 miles from the Mississippi the party passed the Hatcha-Lucha (Black Creek) and about 168 miles they crossed the Pascagoula (now Chickasawhay) a little above where the Slapacha (Leaf River) falls in. This last is called Estopacha in other documents of the time. Thence on nothing special occurred until they reached the Mobile River, where the guide line had diverged 517.44 perches too far north.
The observatory had been erected before Ellicott's arrival from New Orleans in his schooner by way of Mobile. Observations (solar and lunar, of Castor and Pollux, &c.) were made from March 18 to April 9, 1799. Here the large sector was used, and the transit and equal altitude instrument also. Finally a boundary stone was set up, marked (according to the Journal) on the north "U. S. Lat. 31° 1799," and on the south "Dominos de S. M. C. Carolus IV. Lat 31° 1799." This piece of brown sand-stone, about three feet high is still in place near the Southern Railway and is the basis of all surveys in south-west Alabama.[151] During this time Gillespie went up the river to St. Stephens. With a Haddley's sextant he determined the latitude of that place, and he also made a sketch of the river. Ellicott himself determined the latitude of Mobile and the point at the mouth of the Bay.
Among the most serious problems of the survey was carrying the line across the Mobile River and adjacent swamps. The only feasible way was found to be for parties on each side to make fire and smoke signals at certain intervals on the high lands to the east and west.