In his editing for the 1837 edition, Joseph Smith emended the agentive founder to the specific noun foundation in four passages. Besides this one in 1 Nephi 13:6, we have the following three cases:
For the initial example (in 1 Nephi 13:6), Joseph was probably influenced by Oliver Cowdery’s two uses of the word foundation just before in 1 Nephi 13:4–5 (see the previous discussion under 1 Nephi 13:4, 5). Besides these four examples of Joseph’s replacement of founder with foundation, there is a fifth example that was introduced into the text by the 1830 typesetter:
The 1981 LDS edition correctly restored the original noun founder in all five of these cases. The RLDS text has restored founder in only one case (1 Nephi 14:9). Beginning with the 1908 edition, the RLDS text has typically followed the printer’s manuscript. In 1 Nephi 14:9, Joseph Smith did not mark the change from founder to foundation in 𝓟 because the change had already been made in the 1830 edition; thus the 1908 RLDS edition restored founder only there.
There is one example that uses the verb found (not the agentive noun founder) to refer to the devil as the one who founded the great and abominable church:
Here, of course, it would be difficult to emend the verb form founded to the noun foundation (or the agentive founder) without significantly rewriting the text.
In addition to these examples involving the devil as founder of the great and abominable church, there are a couple of references to Alma as the founder of the church among the Nephites:
Summary: The original text consistently refers to the devil as the founder, not the foundation, of the great and abominable church; Joseph Smith’s editing of founder to foundation in 1 Nephi 13:6 was probably influenced by Oliver Cowdery’s immediately preceding changes of formation to foundation in 1 Nephi 13:4–5.