Simpson resigned from a prestigious New York City pastorate to develop an interdenominational fellowship devoted to serving unreached people.

[9] After more than a decade of nomadic address changes for the Institute—including Eighth Avenue and 44th Street in Manhattan—28 acres of land were purchased in Rockland County, New York, and, in 1897, the school relocated to the village of South Nyack becoming widely known as a Bible college and an institute for ministry preparation.

The Missionary Training Institute was later granted a charter by the New York Board of Regents[10] and the school's curriculum was registered by the State Education Department in 1944.

The school changed its name to Nyack College in 1972 and began offering professional degree programs like education and business in the early 1970s.

Steady growth in enrollment prompted a search in 2008 for a new permanent home for the New York City campus, an initiative that became known as The Miracle in Manhattan.

[12] In 2012, Nyack College and Alliance Theological Seminary signed a 20-year lease[13] with a two-year option to purchase the 166,385 sq ft (15,457.7 m2) on eight floors of the structure at 2 Washington Street in historic Battery Park.

[21] Through a collaboration with Hudson Link for Higher Education in Prison, Alliance University provided a Bachelor of Science program in organizational management to incarcerated individuals at Fishkill Correctional Facility in Beacon, New York and at Sing Sing Correctional Facility in Ossining, New York.