Today's OED antedating: "jittery"

Jittery, colloquial, nervous ("jitter," n., sec 2, first use cited 1931): Essay titled "Football Rules or Whatever They Are," by Robert C. Benchley, Detroit Athletic Club News, October 1929, pp 22-23: "For after the war the Rules Committee began to get jittery. They acted as if they thought somebody was following them."