Spears were centrally relevant through the 1600s as part of pike and shot warfare, and even then only went away with the advent of bayonets for firearms. With as long as standard muskets stayed, as well as the continued use of formation tactics and existence of cavalry on the battlefield, these bayonets carried on in use and form factor as spears through the middle of the 1800s.

Modern bayonets and rifles are short enough and used differently enough they are a distinct type of weapon, but that evolution is relatively recent.