1620s, in a military sense, "soldier employed in building fortifications, field-works, etc.," agent noun from sap (v.1).
"to travel from place to place," 1590s, from Latin peregrinatus, past participle of peregrinari "to travel abroad, be alien," figuratively "to wander, roam, travel about," from peregrinus "from foreign parts, foreigner," from peregre (adv.) "abroad," properly "from abroad, found outside Roman territory," from per "away" (see per) + agri, locative of ager "field, territory, land, country" (from PIE root *agro- "field").
1570s of armies; from 1882 in field sports; by 1905 in the political sense (compare left wing). Right-winger is attested by 1919 in U.S. politics; 1895 in sports.