According to this they were apparently called Mahometans during the colonial era in North America. What were they called before this, and when/why did the term Muslim catch on?
Muslim (مسلم) is the Arabic term found in the Quran, meaning one who submits, Islam means submittance. Mahometan comes from a spelling of Muhammad and identifies them as being followers of the prophet Muhammad, just as Christians are followers of Christ. Ive actually only ever seen it used in my studies by some classical philosophers, Montesquieu comes to mind. So, when was Muslim first used to refer to followers of Islam? By Muhammad himself throughout the Quran
The word “Muslim” is borrowed from its Semitic roots in Arabic and Hebrew, and long story short, means “one who submits (to the word of God).”
The original word source is salaam which in Arabic is used both for “peace” and as part of a greeting meaning roughly “peace be upon you” (cognate to the Hebrew term shalom). The root of this is the sound pattern slm, which represents peace or submission. The pattern of the sound of i, then the root, then aa, constructs a term for performing the act of doing whatever the root-word is, so islmaa would be the act of submitting, and became “Islaam” or “Islam” in English. The pattern of the sounds mu, then root, then i, constructs an active participle that describes doing an action. In this case, muslmi is the active participle for “one who submits” and became “Muslim” in English (also seen as “Moslem” and similar in many cases, especially older ones).
A second term, which is pretty much identical in origin to the above and which you will find in archaic usage, is Mussulman. This is seen in English at times, where it is likely a step removed from the original Arabic. This version of the term (and its variants) is what is found in all of the Romance languages, as well as some of the other big European languages, and likely entered English usage through those intermediary steps.
The other term found especially often in older texts in, “Mohammedan” and its variants, such as “Mohometan,” are all essentially the same thing – various transcription of the name Mohammed, with the “an” following it to suggest a follower. Much as Christian is a follower of Christ, Mohammedan was meant to suggest a follower of Mohammed. There can be debate over whether this is an accurate description, but it was not by any means intended to be disrespectful at the time.
100 years ago here are some of the terms used: