Moses Harlan [George, James] was born 20 February 1682/83. The History and Genealogy of the Harlan Family by Alpheus Harlan states that he was born in "the Parish of Donnahlong," County Down, Ulster, Ireland.

Moses was the son of George Harlan and Elizabeth Duck. When his parents married the handwritten certificate was read as Donnahlong by researchers who have perpetuated the improper Parish name. An experienced evaluation reads "Donnahclony" with the writing running the "h" and "c" together. The proper spelling is Donaghcloney. This compiler believes after viewing the marriage certificate of George Harlan, that Moses Harlan was born in the Parish of Donaghcloney, County Down, Ulster, Ireland.

When Moses was about four or five years old his family traveled to Belfast and sailed to New Castle, Province of Pennsylvania, now Delaware. His parents settled on Brandywine Creek where they were among the first Society of Friends at Centre Meeting near present Centreville, Delaware.

Moses Harlan married Margaret Ray about 1712 at Newark Monthly Meeting which became known as Kennett Monthly Meeting in 1760. Moses and Margaret’s first daughter, Mary was born about 1713. Moses and Margaret also had a younger daughter named Rebecca. In 1714 Moses father, George died. Moses paid tax’s in Kennett Township in 1715

By 1724 the Harlans were paying tax in London Grove, Chester County, Pennsylvania. In April 1727 Moses and Margaret sold 280 acres on Conewago, Creek, Menallen Township, Lancaster County, Pennsylvania [now Adams County, Pennsylvania] to Henry Woodward. The land was a portion of land Moses received from his father. They sold another 200 acres on Conewago Creek to Charles and Francis McClure. In 1729 Lancaster was formed out of Chester County.

In 1745, he received a 855 acre patent on the upper fork of Conewago Creek in Menallen township, Lancaster. Conewago is an Indian word meaning "at the place of rapids" (Conewaugha). About 1740 daughter Rebecca married John Blackburn. Moses conveyed 250 acres to his son-in-law in July 1747.

Moses sat down in October 1747 and wrote his will. The will states that he is weak of body but was of good memory. Moses instructed his son-in-law John Blackburn to appoint his executors., Moses provided his grandson Jacob Cox 200 acres on the north side of Conawago Creek with instructions for Jacob to pay his sisters each five pounds. If Jacob should die then the lands were to go to any male heirs that Jacob’s mother Mary might have and if not to be divided by the sisters or survivors of their heirs. He left his 2 year old bay mare to granddaughter Dinah Cox. He gave grandson’s Thomas and Moses Blackburn 100 acres on the south side of Conawago Creek. Moses instructed his wife Margaret to hold the remaining lands and all worldly goods and chattles. His will was probated March 1749 in Menallen township, Lancaster County, Pennsylvania [now Adams County].