Webster’s Revised Unabridged Dictionary · 1913
Thereupon
There′up·on′ (·ŭp·ŏn′), adv. 1. Upon that or this; thereon. "They shall feed thereupon." Zeph. ii. 7.
2. On account, or in consequence, of that; therefore.
[He] hopes to find you forward, . . . And thereupon he sends you this good news. Shak.
3. Immediately; at once; without delay.