Mary "Polly" W. Koontz was born on June 22, 1776, in Virginia. She married Gavin Allison in 1804. Gavin was born on January 29, 1759, in Lancaster County, Pennsylvania. During the Revolutionary War, Gavin served in the Virginia Militia and later the Washington County Pennsylvania Militia. He served as a private in the 4th Company, 3rd Battalion, of the Washington County Militia, beginning 1781. He lived in Cecil Township at the time. Prior to 1781, the area where Gavin lived was claimed by Virginia and Pennsylvania. The boundary was settled in 1781 with the creation of Washington County, Pennsylvania. After the death of Gavin's father, John Allison, on March 25, 1790, Gavin inherited 50 acres of land in Canton Township, Washington County. On August 8, 1804, Gavin and Mary "Polly", sold to Walter Maxwell, for $400, 80 acres of land (which included 30 acres Gavin acquired on May 31, 1804), in Canton Township. By 1810, Gavin and Mary lived in Mount Pleasant Township, in Washington County. On April 20, 1813, Gavin bought 20 acres of land from James and David Miller, apparently located in Mount Pleasant Township. On December 13, 1817, Gavin and Mary sold this 20 acres of land to Andrew Miller, for $302.19. In 1820, Gavin and Mary resided in St. Clair Township, Allegheny County, Pennsylvania. In 1834, Gavin and Mary moved to Mercer County, Pennsylvania. Gavin Allison died on December 28, 1838, in Clarksville, Pennsylvania. He was buried in Old Glenwood Cemetery in Clarksville. The site of Clarksville is now under the Shenango Reservoir, created by the completion of the Shenango Dam in 1965. Gavin Allison's grave plot was moved to New Glenwood Cemetery, in Clark. Clark replaced the flooded site of Clarksville. After Gavin's death, Mary lived with her son, Jonathan N. Allison, in Delaware Township, in Mercer County. By 1860, Jonathan and his family had moved to Rush Township, Jo Daviess County, Illinois. Mary "Polly" W. (Koontz) Allison died on December 14, 1865, in Elizabeth, Jo Daviess County, Illinois. She was buried in Long Hollow Cemetery, Elizabeth, in Jo Daviess County, Illinois.

Children:
1. John, m. Mary Stewart
2. Nancy Jane, b. 11 August 1805 (Washington County, Pennsylvania); m. John T. Young, 31 May 1827
3. Thomas, m. Eliza Hodge
4. James Henry, b. 6 February 1809 (Washington County, Pennsylvania); m. Eliza Jane Gettis, 22 October 1833
5. Samuel K, b. 1811; m. Hanna Hamilton
6. Jonathan N., b. about 1813 (Pennsylvania); m. Lydia Koonce
7. Mary Brownlee, b. 1817 (#84377066); m. Richard F. Clark, 1839
8. Unknown son