Andrew Lynn, Jr., the eldest son of Andrew Lynn, was born between the years 1728-1732. Both have been used in different articles. The exact date and the exact location are not known. However, he was born in New Jersey.

Andrew Jr. developed into a leader of men and his achievements were frequently striking and dramatic. He fought under Col. Cresap. His brother William did also. In the battle at Negro Mountain in 1757, he and William were volunteer rangers in Capt. Alexander Beal’s Company. They were also volunteers in 1758 in the General Forbes campaign that resulted with the expulsion of the French from the Monongehela region and the taking of Fort Duquesne. In it, they served under Captain Evan Shelby, father of Isaac Shelby, governor of Kentucky.

Andrew Jr. made his first settlement on Redstone Creek in the 1760’s. He tomahawked a claim to a large tract of land on both sides of the Redstone Creek. This is in what is now Redstone and Jefferson townships. This tract of land was later known as "Crabtree Bottom". In the New Purchase the number of this tract is 2051, granted April 5, 1769, and surveyed August 22, 1769. It was the first survey of land in what is now Fayette Co., Pa.

Before his coming to Fayette Co., Andrew Jr. was married to Mary Ashercraft Johnson, daughter of Peter and Mary Johnson of Maryland. They were wed in 1760.

Several times Andrew was driven back over the mountains by the Indians. He did not permanently settle on the Redstone until late 1766 or 1767. The proof of this are the records that show that some of his children were born in Maryland.

Tradition tells us that Andrew Jr. lived in the trunk of a hollow sycamore tree that stood near the shore of Big Redstone Creek. There is one other Andrew that this story is also told about.

Through hard energetic labor and great perseverance and rare good judgment, Andrew Jr. added to his already large land possessions several enjoining tracts of land on Redstone Creek, and many acres along the Monongehela River, until he had several hundred acres. He was one of the largest landowners for that part of Fayette Co. From time to time he would ask for surveys and was granted patents for his additional tracts of land.

Additional surveys to Andrew Lynn Jr. in 1769 are as quoted: "To Col. Andrew Lynn, Jr. , in right of Nathan Lynn, 292 ½ acres, called "Contention", situated on the east side of the Monongehela River, in the New Purchase, Bedford County, and surveyed August 25, 1769 by order of survey 492, dated April 3, 1769. Also, to Col. Andrew Lynn, Jr., in right of Thomas Pierce, 130 ½ acres, called "Purchase", situated on the east side of the Mongehela River, in the New Purchase, Bedford County, and surveyed August 25, 1769, by order of survey 1768, dated April 3, 1769."

The first named survey was made by Archibald McClean, Deputy Surveyor, and the last two by A. Lane, Deputy Surveyor.

Col. Andrew Lynn, Jr. bought land not only on the Redstone but a tract below there in what is now Washington Township, Fayette Co., Pa. He lived for a while on this last tract. It was sold to him by Thomas Pierce and conveyed to him by deed, dated August 20, 1769. Thomas Pierce entered an application for the tract on April 3, 1769. An order of survey was issued to Col. Andrew Lynn, Jr. on June 3, 1788 and a patent for 130 acres was granted on March 1, 1790.

Col. Andrew Lynn, Jr. increased his original lands by the purchase of an adjoining tract tomahawked by William Lynn, his brother. This entire farm of 450 acres later came into the possession of his son, Andrew Lynn, Esq., who lived upon it from 1774 until his death in 1855. This tract of land was called "Sedgy Fort" from an Indian or a prehistoric fort that stood upon it.

Andrew Jr. was put into military service for the Revolutionary War in great haste. Officers found him plowing in the field with his wife. His two young sons were in the adjacent woods gathering firewood. They carried him off, refusing him permission even to go home to change clothes. Andrew Jr. remained in the service for five years. He was appointed wagon-master on January 9, 1778 in Westmoreland County, Pa. He later rose to the rank of Colonel.

In 1785, Andrew Jr., with his son William, and a party of neighbors, made a trip to the Hocking River in Ohio and began tomahawking claims to the land along it. They were attacked by Indians and escaped by swimming the river. However, William had his arm shattered by a bullet from an Indian gun.

About 1790 Andrew Jr. moved across the creek into Redstone Township and lived near the home of James M. Lynn, his nephew, until his death in 1794. After his death, his widow enlarged the Lynn land possessions by the purchase of adjacent hilly tracts. She survived Andrew for many years. She spent her declining years at the home of her eldest son, William. She was buried beside her husband in the old family burying ground upon the farm where she and her husband had lived as pioneers many years before.