Its historical importance comes from not just over a century of use as church, but its centrality in the struggle by modern preservationists to save and restore the city's many landmark buildings.

The edifice occupies a commanding situation... Owing to the immediate and rapid descent of the ground east of the site, the basement line of the portico is above the top of the buildings between it and the river; so that the full effect of its architecture may be seen while passing the town...[5]The southward orientation of the columns and facade, the direction in which most shipping approached the city, was meant to echo the similar marine outreach of the Parthenon or the Temple of Poseidon at Sounion in Greece.

[5] The original design included a small dome atop the roof, which Davis explained thus: The gigantic portico, and lofty dome…will henceforth serve as a conspicuous and characteristic landmark, indicative of the taste, discrimination, and sense of classical beauty, of the inhabitants of Newburgh.

[6][9] The mortgage payments did not prevent the church from expanding the property, with a small Gothic Revival parsonage being erected on the southeast corner in 1852, where the library now stands.

The church put the money it could now spend more freely to work on the structure, adding a pastor's study and recessed pulpit and repainting the interior (not completely enough; some of the original stenciled Greek motifs are still visible today).

It was able to purchase an organ and add 20 feet (6.1 m) onto the north side of the building, complete with brick transept arms designed by George E. Harney.

In 1909 an iron fence was built with money paid to the church by the city for the use of its lawn during the previous year's Fulton-Hudson celebration.

The following year cement replaced wood as the flooring material for the portico, and in 1920 all lighting in the building became electric when the chandeliers switched from gas.

While the church was able to repair it and in fact make further improvements such as adding telephone service and a public address system, the years had taken their toll and in 1964 the congregation had acquired land in the Town of Newburgh on which to build a new edifice.

[10] Public efforts against its demolition led to the church's addition to the National Register of Historic Places in 1970, which meant that federal funds could no longer be used to demolish it.

The battle to save the church revived this tradition and marked the beginning of the city's modern historic preservation movement.

The following year the state expanded the city's historic district to include the church, while the NPS removed the column's Ionic capitals.

Hillary Clinton, then First Lady, spoke in front of the church before a large crowd on July 14, 1998, as part of the Save America's Treasures tour.

[10] The $128,205 federal grant received as part of that program paid to stabilize the church's upper gallery, which was then in imminent danger of collapse.

On August 7, 2001, the church was designated a National Historic Landmark by the Department of the Interior after a successful application by state preservation official William Krattinger.

[12] The picket fence was repainted in 2004, and the following year the World Monuments Fund put the church on its list of the 100 Most Endangered Sites.

In 2002 the NPA commissioned the Albany firm Mesick Cohen Wilson Baker to do a Historic Structure Report summarizing what needed to be done to restore the building.

Estimates for implementing all the suggestions of the Historic Structure Report and completely restoring the church have ranged as high as $8 million.

[17] In 2006 the Newburgh Preservation Association, with a grant from the Dyson Foundation, commissioned an Adaptive Re-Use Study to outline potential uses.