nationalist n.

"of or pertaining to a nation or a country regarded as a whole; established and maintained by the nation; peculiar to the whole people of a country," 1590s, from French national (16c., from Old French nacion), and also from nation + -al (1). Opposed to local or provincial (or in the U.S., state).

Meaning "peculiar or common to the whole people of a country" is by 1620s. From 1802 as "established and maintained by the nation or its laws." As a noun, "citizen of a (particular) nation," from 1887. Related: Nationally. 

National guard is from 1793, originally in reference to an armed force in France identified with the revolution; U.S. use is from 1847, originally a name sometimes given to the organized militia. National anthem is recorded by 1806. 

A King though he's pestered with cares,

    For the most part he's able to ban them;

But one comes in a shape he never can escape—

    The implacable National Anthem!

[W.S. Gilbert, "His Excellency," 1894] 

word-forming element meaning "one who does or makes," also used to indicate adherence to a certain doctrine or custom, from French -iste and directly from Latin -ista (source also of Spanish, Portuguese, Italian -ista), from Greek agent-noun ending -istes, which is from -is-, ending of the stem of verbs in -izein, + agential suffix -tes.

Variant -ister (as in chorister, barrister) is from Old French -istre, on false analogy of ministre. Variant -ista is from Spanish, popularized in American English 1970s by names of Latin-American revolutionary movements.

1844, "devotion to one's country, national spirit or aspirations, desire for national unity, independence, or prosperity;" see nationalist + -ism; in some usages from French nationalisme. Earlier it was used in a theological sense of "the doctrine of divine election of nations" (1836). Later it was used in a sense of "doctrine advocating nationalization of a country's industry" (1892). An earlier word for "devotion or strong attachment to one's own country" was nationality (1772).

To place the redemptive work of the Christian Faith in social affairs in its proper setting, it is necessary to have clearly in mind at the outset that the consciousness of "the nation" as the social unit is a very recent and contingent experience. It belongs to a limited historical period and is bound up with certain specific happenings, theories of society and attitudes to life as a whole. [Vigo A. Demant, "God, Man and Society"]