[1] The church is situated near the center of New Castle at the northeast end of the Green, or town common, making it a prominent local landmark and tourist attraction.

Immanuel Church was founded in 1689 as the first Anglican parish in the present-day state of Delaware, which at the time was still part of Pennsylvania.

In 1820, Philadelphia architect William Strickland undertook a major renovation and expansion of the building which included a new transept, bell tower, steeple, roof, and interior.

[2] The National Register of Historic Places listing for the New Castle Historic District describes Immanuel Episcopal Church as a "stuccoed stone, 5 bay, center aisle church with clipped gable roof, and stone and frame spire with clock".

[1] The current appearance of the building is mostly due to architect William Strickland, who was responsible for the transept and crenellated tower.