1.  Samuel Evans.  History of Lancaster County, Pennsylvania... (online at Ancestry.com).  In Chapter XLVII, under the heading "East Donegal Township":

On the first day of August, 1769, Jacob Downer, who laid out the town, gave to Christian Fox and Garret Fiscus a lot of ground for the use of "the congregation of the Reformed Church of the High Dutch Protestants of Maytown," two lots of ground measuring sixty-two and one-half feet each on the south side of Elizabeth Street, and two hundred and fifty feet deep.  The first pastor was Rev. ___ Hinkle, the second Rev. Ludwig Cupp, who preached for the congregation until 1797.

2a.  Census Index:  U.S. Selected Counties, 1790 (Broderbund CD-311):

1790

Hop, Ludwig

PA

Lancaster Co.

Manor Twp.

p. 140

As read in the film (next source), it is definitely "Hop," not "Kop," so this may not be our subject.  But "Kopp" and "Kop" are common variants of "Cupp," and it's a short road from "Kop" to "Hop."  (As for the discrepancy between the page numbers in the Broderbund index and the NARA film, I've never figured it out, but it makes the page numbers in the index useless.)

2b.  NARA.  1965.  Population Schedules of the First Census of the United States, 1790:  Roll 8, Pennsylvania, Volumes 1-5.  Microcopy No. 673.  National Archives Microfilm Publications, Washington, DC, as contained on Family Quest Archives:  Pennsylvania Federal Census 1790:  Berks, Chester, Delaware, Huntingdon, Mifflin (part), Luzerne, Dauphin, Northampton, Cumberland, Fayette, Westmoreland (part), Bucks, and Lancaster Counties.  Heritage Quest CD M637-8.

1790

PA

Lancaster Co.

Manor Twp.

p. 31

Ludwig Hop

1-1-2-0-0

These data indicate:

Gender and Type	Age Class	Therefore Born	Individuals Inferred
1 free white male	16 or over	in or bef. 1774	= Ludwig
1 free white male	15 or under	1774-1790	= son
2 free white females	all ages	in or bef. 1790	= wife