On October 18, 1819, Mr. Joseph Eastburn founded the Mariners' Church in a loft near the foot of Market Street in Philadelphia. Eastburn's congregation was composed of seamen--his was the second mission for seamen in America. In 1824, the congregation moved from the sail loft to a new church on Water Street above Walnut. In 1830 the mission was organized as an independent church. In 1854, it became a Presbyterian church under the Philadelphia Presbytery. Mariners' Church moved again in 1868, this time to the corner of Front and Union (now Delancey) Streets. In 1959, Mariners' Church merged with Third and Scots Church, forming Third Scots and Mariners' Church, which stands at the corner of Third and Pine Streets and is better known as Old Pine Street Church.

The Seamen's and Landsmen's Aid Society was incorporated in 1878, with "the Spiritual, Moral and Temporal welfare of Seamen and Landsmen" as its object. It maintained a reading room at Mariners' Church for the benefit of the sailors who constantly passed through the port of Philadelphia. In 1965 the Society voted to transfer its assets to the Conwell School of Theology and the Friends of Old Pine Street Church.