John Hall Magowan (1829–1898) was pastor of the Fifth Avenue Presbyterian Church, New York City, from 1867 until his death in Bangor, County Down, Ireland.

In 1848 his father died; despite financial hardships his mother insisted he complete his religious studies and in 1850 he was ordained a Presbyterian missionary.

[2] From 1849 he spent three years as a student missionary in Connaught, a west coast province of Ireland that had been badly affected by both the Great Famine and the fever; small tenant farmers were being evicted by landlords and many of the young men were emigrating to escape the deprivation and poverty.

The southern and western areas of County Armagh had suffered in the Great Famine, but the worst was over by the time Hall arrived.

[4] He travelled extensively, holding prayer meetings and sermons in remote locations, gradually increasing the size of his congregation.

In 1855 he put his experience of journalism to good use, editing the Children's Missionary Herald of the Presbyterian Church in Ireland.

[5] From about 1862 he edited a monthly magazine called the Evangelical Witness; this featured contributions from leading churchmen, and it became an influential publication.

By 1872 the Fifth Avenue church on the corner of 19th Street was no longer large enough to accommodate the growing congregation, and plans were made to build a new one further up-town.

Newspaperman Robert E. Bonner identified a site on Fifth Avenue and Fifty-Fifth Street and made a large financial contribution towards the construction costs.

[8] Despite his heavy workload, Hall was involved with several activities outside the Fifth Avenue Church, these included being the chancellor of the University of New York – a post he held for ten years; he was a trustee for the Princeton Theological Seminary and the Wellesley College plus chairman of the Presbyterian Board of Home Missions and member of the Board of Church Erection.

In 1891 a dispute arose between the seminary and The General Assembly of the Presbyterian Church over the appointment of Charles Augustus Briggs, who was later accused of heresy.

Warszawiak, who had initially trained to be a religious leader in the Jewish faith, had been christened by Scottish missionary Daniel Edwards in 1889.

He joined the Fifth Avenue Presbyterian Church and received support for his work from the New York City Mission and Tract Society.

A committee appointed to review his suitability rejected his application and questioned his integrity; a senior member of the church even employed a private detective to follow and report on his activities.