THE FIRST UNITED PRESBYTERIAN CHURCH of Greenville, Mercer County, Pennsylvania, is the oldest in the town by nearly a quarter of a century.  It was organized in the early days of the last century [1801].  As early as 1790 the fertile lands of Mercer County were attracting the attention of the Scotch-Irish people of Westmoreland and Washington counties and a number of families from these counties settled along the banks of the Shenango.  These families not only came with their oxen, they axes, their spinning wheel and loom, but they also brought their Bibles, their Psalm-books and their catechisms; and what is still better they brought in their hearts as warm and fervent love for Christ and His Church. 

The Chartiers Presbytery of the Associate Church was formally organized, June 23rd, 1800.  Under its care were all the congregations and vacancies west of the Allegheny mountains.  In connection with this presbytery and about this time begins our history.  In the year 1801, Rev. Daniel McLean, a recently ordained minister of the presbytery, visited the Shenango valley and preached at several points in Crawford and Mercer counties.  A region of country, lying nearest the Shenango river and a settlement on Sandy Creek, was called the "Big Vacancy." In this region were a few families who belonged to the Associate Church.