1630s, "to mark out, distinguish," a sense now obsolete, modeled on French remarquer "to mark, note, heed," formed in French from re-, here perhaps an intensive prefix (see re-), + marquer "to mark," which probably is from Frankish or another Germanic source such as Old High German marchon "to delimit" (see mark (n.1)).
Meaning "take notice of, mark out in the mind" is from 1670s; that of "make a comment, express, as a thought that has occurred to the speaker or writer" is attested from 1690s, from the notion of "make a verbal observation" or "call attention to specific points." Related: Remarked; remarking.
1650s, "fact of being worthy of comment," also "an act of observation" (a sense now obsolete), from remark (v.). The meaning "a verbal or written notice or comment" is from 1670s; the sense of "observation, notice" also is from 1670s.