The blog at Open Bible did a neat little experiment a few years ago, using a random sample of 300,000 church names to look at some of the naming patterns of churches in the U.S.
Looking at their data, you can see the different branches of Christianity favor their own naming conventions. The Catholics tend to use the names of saints, while some of the Protestant denominations are a little more straightforward and descriptive, and often use their location and the order they were founded in their names. That is, the “First Baptist Church of [Town]” got that name because it was the first Baptist church founded in that area.
Open Bible found that "'First' appears in 12 percent of Baptist church names, 10 percent of Methodist church names, and fully 21 percent of Presbyterian church names.” Overall, “First Baptist” was the most common name in their dataset, with 5115 churches using that term.
“Second” and “Third” churches aren’t all that rare if you look around, and sprout up when there are too many people for just one church or when part of the congregation splits off. The Second Baptist Church of Detroit, for example, was founded when 13 former slaves left the city’s First Baptist over its discriminatory practices. The numbers can keep climbing if there are enough members of a denomination around, or enough splits among them. Philadelphia has a Tenth Presbyterian and Los Angeles has a Twenty Eighth Church Of Christ Scientist.