This is a template created with the purpose of presenting the entire landscape of Christianity within the United States. For this template, we will use the word "Christian" in a broad sense, that is, anyone who claims to be Christian or have a Christian heritage. However, movements that are part of the New religious movement or are otherwise very loosely linked with Christianity will not be presented here.
Within this template, traditions are ordered (top to bottom) based on the year/century they have their origin. This order is not tied with their origin in the US in particular, but as traditions in general. This, however, does not apply to individual denominations, as you could have a Pentecostal denomination which is older then a Lutheran denomination (as the year of foundation is concerned) and still be lower then that Lutheran denomination because the Lutheran tradition is older then the Pentecostal one.
Every denomination within a tradition or subset of a tradition is ordered in alphabetical order.
Significan denominations that are the largest (as the number of members is concerned), or most prominent in their tradition will be highlighted like this in order for them to be more easily spotted.
When a tradition has a wikipedia article dedicated to its history or presence in the United States, a link to it is added under the tradition's link (exemple: a link to Eastern Orthodoxy in North America is made like this "(Main article)" under the Eastern Orthodox link).
Significant subgroups of specific denominations are in parentheses after the main denomination from which they are part of (exemple: the Albanian, Bulgarian and Romanian Dioceses inside the Orthodox Church in America).
When clarifications are needed, or when the placement of a denomination in a tradition is more controversial, use a note to address the issue (exemple: Old Catholic churches being placed inside the Catholic tradition with the note: "Not in communion with the rest of the Catholic Church").
Anyone who wants to add a new denomination has to look up what tradition is that denomination part of and add it in its specific section (exemple: when adding Lutheran Church–Missouri Synod put it in the Lutheran tradition).
If the tradition is somehow uncertain, or the denomination could be said to belong to multiple traditions, then it goes into the section "Other".
If the denomination is a merger of other two or more denominations that are of different traditions then it goes into the "United" section (exemple: United Church of Christ). However, if the merger denomination is formed from two or more denominations of the same kind, then it goes into the same tradition from where the merger churches were part of (exemple: Evangelical Lutheran Church in America).
Although the distinction between liberal and conservative denominations is a very significant one, due to its controversial and subjective nature, this distinction will not be made in this template.
The distinction between evangelical and mainline protestant denominations will also not be made here. The reason is that this classification is somehow useless as the words changed their original meaning.
The two words are not mutually exclusive.
"Evangelical" used to refer to a movement caracterised by the belief in a necessary born again conversion experience.
"Mainline" used to have a historical meaning, that is, churches that were the original or the most significant denomination in their particular traditions.
Thus the Methodist Episcopal Church would have been classified as both.
With the time, in the US, "Mainline" became synonymous with "Liberal" and "Evangelical" with "Conservative".
Denominations such as the Lutheran Church–Missouri Synod, which do not belive in a "born again" conversion experience, are labeled "evangelical" just because they are conservative.
Other denominations which are historical such as the conservative Southern Baptist Convention (founded in 1845 and the largest baptist denomination in the US) are not considered "mainline" while the Association of Religion Data Archives does classify the more liberal Cooperative Baptist Fellowship (founded in 1991 which represents a small minority of baptists in US) as "mainline".
If you don't have the time to search for the specifics of a denomination, just add it in the "Unclassified" section and some other editors will find the time to classify it.