In scheme theory, an algebraic scheme is the data of a scheme + a morphism of finite type to the spectrum of a field. Where does the term "algebraic scheme" come from? It does not seem intuitive to me (to me all schemes are equally algebraic, others may have a different opinion). Are there any historical accounts regarding this matter?

Here is one mention of the category of algebraic schemes without an explicit reference to the base (though it appears that in that terminology all schemes are understood to come with a morphism to the spectrum of a field). In the Stacks Project, they use "algebraic $k$-schemes" (with $k$ being a field).