Leonard Propst, Sr. was born in 1737 in Lancaster, Pennsylvania. He was the second youngest of four children to parents Johann Michael Propst and Anna Marie Keller.
In 1760, Leonard married Mary Catherine Miller in Pendleton County, Virginia (now West Virginia). They went on to have five children together:
- Leonard Propst, Jr. (b. 1760)
- Barbara Propst (b. 1768)
- George John Propst (b. 1770 – d. 1823)
- Mary Magdalena Propst (b. 1772 – d. 1818)
- Christina Esther Proppst (b. 1775)
Leonard was a landowner in Pendleton County. As can be seen on the attached list of landowners and holdings, he owned a great deal of land and was surrounded by his siblings and children in the area. (Leonard’s holdings are listed under the name Leonard Propst, Sr.)
In 1801, Leonard died at Winfield Propst’s house near Propstburg, in Pendleton County, West Virginia.