|Resting place||Spring Grove Cemetery|
Israel Ludlow was born near Morristown, New Jersey in 1765. In 1786, each of the thirteen states was to appoint a man to help survey the Seven Ranges in the easternmost portion of the Northwest Territory under the Land Ordinance of 1785. Ludlow was appointed to fill the vacant South Carolina surveyorship. Ludlow was one of two surveyors to stay in settlements near the Ohio River the winter of 1786–1787, and completed the survey of the seventh range, plats, and notes by August 1787.
Later in 1787, a land company called the Ohio Company of Associates contracted with the Congress of the Confederation to buy a 1,500,000-acre tract along the Ohio River to the west of the Seven Ranges. Ludlow surveyed the north line of this tract that is known as Israel Ludlow's Survey.
Virginia was granted lands between the Scioto River and Little Miami River in Ohio for bounties for its war veterans in a tract called the Virginia Military District. John Cleves Symmes purchased a large tract between the Little Miami River and the Great Miami River called the Symmes Purchase. Symmes had Ludlow survey a line between the sources of the Scioto and Little Miami to determine the boundary between the tracts, afterwards known as the Ludlow Line, the subject of decades of legislation and court action due to the difficulty in determining the source of the Scioto River.
On August 25, 1788, Matthias Denman, Robert Patterson, and John Filson entered an agreement to found Cincinnati, with Ludlow taking Filson's place upon his death. The town was settled December 28, 1788 by Ludlow and twenty-six other people. He surveyed the town by January 1789.
When Hamilton County, Ohio was formed January 2, 1790, Ludlow was named clerk. In 1790, Ludlow established the community of Ludlow's Station. In 1794, as proprietor, he laid out Hamilton, Ohio, and in 1795, with Governor Arthur St. Clair, Jonathan Dayton, and William McMillan, he planned Dayton, Ohio.
In 1796, Ludlow married Charlotte Chambers of Chambersburg, Pennsylvania. That year he built the largest house in Cincinnati, known as the "Ludlow mansion". Israel and Charlotte had four children: James Chambers Ludlow (1797–1841), Martha Catharine Ludlow (1799–1834), Sarah Bella Ludlow (1802–1882), and Israel L. Ludlow (1804–1846).
One historian said: "By the time of his death in the early 1800s he had surveyed more land in the Ohio Country than any other federal surveyor." His remains were later moved to Cincinnati's Spring Grove Cemetery. Hamilton, Dayton, and Cincinnati each have a street named after Ludlow. Ludlow Falls near Dayton is also named after him. Two streams named Ludlow Creek are in Miami County, Ohio and Greene County, Ohio. Ludlow, Kentucky, directly across from Cincinnati, Ohio, also bears his name.
- Greve 1904 : 165
- Pattison 1959 : 127
- Pattison 1959 : 132-133
- Peters 1918 : 249
- Peters 1918 : 162
- Peters 1918 : 112-117
- McFarland 1904 : 278-280
- Drury 1909 : 36
- Nelson 1894 : 56-57
- Greve 1904 : 186
- Drury 1909 : 52
- Goss 1912 : 74
- Steele 1896 : footnote page 213
- Overman, William Daniel (1958). Ohio Town Names. Akron, OH: Atlantic Press. p. 78.
- Ohio Department of Natural Resources. "GAZETTEER_OF_OHIO_STREAMS" (PDF).
- Greve, Charles Theodore (1904). Centennial history of Cincinnati and representative citizens. Vol. 1. Chicago: Biographical Publishing Company.
- Pattison, William D. (1959). "The Survey of the Seven Ranges". The Ohio Historical Quarterly. 68: 115–140. Archived from the original on 2014-11-01. Retrieved 2014-11-01.
- Peters, William E. (1918). Ohio Lands and Their Subdivision. W.E. Peters. p. 249.
- Drury, Augustus Waldo (1909). History of the city of Dayton and Montgomery County, Ohio. Vol. 1. Dayton: S J Clarke Publishing Company.
- Goss, Charles Frederic (1912). Cincinnati, the Queen City, 1788-1912. Vol. 1. Cincinnati: S J Clarke Publishing Company.
- McFarland, R W (1904). "The Ludlow Line". Ohio Archaeological and Historical Publications. 13: 278–280. Archived from the original on 2014-11-01. Retrieved 2014-11-01.
- Nelson, S B; Runk, J M (1894). History of Cincinnati and Hamilton County, Ohio. Cincinnati: S B Nelson and Company. p. 56.
- Steele, Robert W; Steele, Mary Davies (1896). Early Dayton: with important facts and incidents from the founding of the city of Dayton, Ohio to the hundredth anniversary 1796-1896. Dayton: United Brethren Publishing.