Question: What was the length, in the 1980's, of the river John J Conway used as a source of water for the settlers to whom he sold land ?

Context paragraphs:
River John: River John is a river in Nova Scotia.  Draining the extreme western part of Pictou County, it flows into Amet Sound on the Northumberland Strait at River John, a village which takes its name from the river.  The Mi’kmaq name is Kajeboogwek (“flowing through desert or solitary place”).  An early name was Deception River.  Its present name is believed to derive from Rivière Jaune, an Acadian name, though it may also derive from nearby Cap Jean (now Cape John).  DesBarres called it River John in his "Atlantic Neptune".

Ridgefield Township, New Jersey: Ridgefield Township was a township that existed in Bergen County, New Jersey.  The township was created in 1871, when Hackensack Township was trisected to form Palisades Township in the northernmost third, Englewood Township in the central strip and Ridgefield Township encompassing the southernmost portion, stretching from the Hudson River on the east to the Hackensack River, with Hudson County to the south.  Much of the area had been during the colonial area known as the English Neighborhood.  As described in the 1882 book, "History of Bergen and Passaic counties, New Jersey," "Ridgefield is the first township in Bergen County which the traveler enters in passing up the Palisades.  His first impressions are much like those of old Hendrick Hudson in speaking of a wider extent of country: "A very good land to fall in with, and a pleasant land to see."  The valley of the Hackensack invited early settlers in the seventeenth century, and the valley of the Overpeck Creek, a navigable arm of the Hackensack, also attracted settlers quite as early in this direction.  Sloops and schooners can pass up this creek nearly to the northern boundary of the township.  Ridgefield is bounded on the north by Englewood, on the east by the Hudson, on the south by Hudson County, and on the west by the Hackensack River.  The southern boundary is less than two miles in extent, and the northern less than four, and the length of the township from north to south does not exceed four miles.  Bellman's Creek, forming part of the southern boundary, the Hackensack, the Overpeck, the Hudson, with more than a dozen other smaller streams and rivulets, bountifully supply the whole township with water.  From the western border of the Palisades the land descends to the Overpeck, forming a most beautiful valley, with the land again rising to a high ridge midway between the Overpeck and the Hackensack.  From this long ridge, extending far to the north beyond this township, it took its name of Ridgefield. <br><br>The New York, Susquehanna and Western, formerly the Midland Railroad, the Jersey City and Albany Railroad, and the Northern Railway of New Jersey—all running northward through the township— afford ample railroad accommodations.  The Susquehanna enters the township at Bellman's Creek, and the Northern at about one hundred feet south of the creek, and at a point north and east of the Susquehanna.  The Albany road in this locality is not yet constructed, diverging at present from the track of the Susquehanna between Little Ferry and Bogota stations.  It has, however, an independent line projected and now under construction to New York City. <br><br>Early Settlements.  Ridgefield embraces the earliest settlements in the ancient township of Hackensack, antedating even the organization of that township in 1693, and of the county of Bergen in 1675.  There seems to have been no town or village compactly built, like the village of Bergen, but there were settlements both of Dutch and English in and about what was subsequently known as English Neighborhood prior to 1675.  The Westervelts, the Zimcrmans, the Bantas, and the Blauvelts, all coming from Holland, settled in the middle of the seventeenth century in that locality.  The ancestors of Jacob P. Westervelt, now of Hackensack Village, with himself, were born in English Neighborhood.  His father was born there in 1776, and was the son of Christopher Westervelt, who was born there certainly as early as 1690, and he was the son of the original ancestor of this family, who came from Holland and settled on Overpeck Creek, within the present limits of Ridgefield township, probably about 1670."

O'Neale v. Thornton: O'Neale v. Thornton, 10 U.S. 53 (1810) is a ruling by the Supreme Court of the United States which held that neither the state of Maryland nor the government of the District of Columbia authorized the resale of foreclosed government land at a price less than the original sale price.  In establishing the District of Columbia, the D.C. government had sold land to original investors at $66.50 per lot.  The investors failed to pay, so the government foreclosed and resold the land to a second investor at the same price.  The second investor failed to pay, so the government foreclosed again and sold the land to a third investor at a price lower than the original sale price.  This third sale, the Supreme Court said, was illegal.  Title should be returned to the second buyer, although the government was still free to seek foreclosure against that buyer on the basis of nonpayment.

Ellsworth-Jones Building: The Ellsworth-Jones Building is a historic building located in Iowa Falls, Iowa, United States.  Eugene S. Ellsworth was a land broker, town developer, and philanthropist.  This building was the headquarters of his firm Ellsworth and Jones, who sold land throughout Iowa and other states in the Midwest.  While Iowa Falls was their headquarters, they also had offices in Chicago, Boston, and Crookston, Minnesota.  The three-story, brick Neoclassical building was completed in 1902.  It features Ionic and Doric columns, egg-and-dart motif on the lower level columns, round arches, acanthus leaf keystones, foliated decorative elements, a dentils on the cornice.

Rio Grande: The Rio Grande ( or ; Spanish: Río Bravo del Norte , ] or simply Río Bravo) is one of the principal rivers in the southwest United States and northern Mexico (the other being the Colorado River).  The Rio Grande begins in south-central Colorado in the United States and flows to the Gulf of Mexico.  Along the way, it forms part of the Mexico–United States border.  According to the International Boundary and Water Commission, its total length was 1896 mi in the late 1980s, though course shifts occasionally result in length changes.  Depending on how it is measured, the Rio Grande is either the fourth- or fifth-longest river system in North America.

Alston (name): Alston is an English language surname of Anglo-Saxon origin with several derivations.  It may have evolved from the Middle English given name "Alstan", the prefix, "Al-" itself derived from different Old English words ("noble", "elf", "old", "shrine", "temple"), and the suffix "-stan" ("stone") derived from pre 7th century Old English.  The oldest public record of this derivation is found in 1279 in Cambridgeshire.  One branch of this name may have been taken from the manor of a Saxon Lord called Alstanus, he had his manor in Stambourne, North East Essex.  It is known that he was still in possession of the Manor after the Norman conquest, although as a tenant rather than owner, he held the land annexed against the King.  There are a high density of families with the surname Alston and Alliston from around the Sudbury area, not far from Stambourne.  In the 1224 feet of fines it is recorded that John son of Adam de Alliston sold land at Stanfeld (Stansfield) Suffolk.  Stansfield is a few miles North of Stambourne.  Both Stambourne and Stansfield may have taken their name from Æthelstan Half-King, Earl of East Anglia in the 930s.

John J. Conway: John Conway founded the city of Mission, Texas in 1907 with J. W. Holt when the two purchased the 17000 acre La Lomita Ranch from the Oblate fathers.  Subdivided parcels were sold to arriving settlers and water was pumped from the Rio Grande by means of a pumping station called the First Lift Station and distributed to the residents of the Rio Grande Valley through the Mission Canal Co.  Irrigation System, also started by Conway and Holt.

Spring creek: A spring creek is a type of free flowing river whose name derives from its origin: an underground spring or set of springs which produces sufficient water to consistently feed a unique river.  The water flowing in a spring creek may additionally be fed by snow pack or rain run-off, as in most traditional free-flowing rivers, but often the entire water source for a spring creek is an aquifer or other underground water source.  For this reason, spring creeks are often filled with very pure, clean water and also demonstrate water flows that are smooth, consistent, and unwavering throughout the seasons of the year - unlike rivers filled with run-off or spring and summer melt-off from snow pack, whose water flows, water clarity, and water conditions often vary highly over the course of the year.  In addition, water temperatures in spring creeks tend to vary less throughout the seasons of the year than traditional creeks and rivers because they are fed by underground water sources.  Because of the depths of these water sources, spring creeks often emerge from their source or headwaters very cold and stay that way over the length of their runs.  In addition, due to the consistent water flows and the fact that spring creek water is "pushed" by the force of pressure from the source rather than "pulled" by the force of gravity downhill, spring creeks can flow through very flat sections of land with minimal depths over grades that might not sustain run-off creeks and rivers.  In these low-grade or flat sections of spring creeks, water flows can appear almost laminar with the surface of the creek appearing to be nearly flat and without the prominent riffles and surface disturbances caused by more rough or uneven surface bottoms found below free-stone run-off creeks and rivers surfaces.

Mahackemo: Mahackemo (or Mahackamo) was chief of the Norwalke Indians, a small tribe of the Siwanoy, who sold land to Roger Ludlow in 1640 (Old Style or 1641 New Style) which later became Norwalk, Connecticut.

Corban C. Farwell Homestead: The Corban C. Farwell Homestead is a historic house at the junction of Breed and Cricket Hill Roads in Harrisville, New Hampshire.  The story wood frame house was built in 1901 by Corban Farwell, a local farmer.  The house is distinctive as a late example of Greek Revival architecture, albeit with a number of Colonial Revival features added, as well as bands of scalloped wood shingles.  Corban Farwell was a purveyor of farm supplies to the summer residents of the resort community that had sprung up around nearby Silver Lake, and also sold land along the lakeshore for expanding that development.

Supporting paragraphs: John J. Conway Rio Grande
Answer: 1896 mi