Complex sentence: Raised by the widow of Newel Knight, Jesse's family was poor throughout his youth, he was handsomely rewarded for his diligence as a prospector with the discovery of the famous Humbug Mine in the Tintic Mining District near Eureka, Utah in 1886.
Split into simpler sentences: Raised by the widow of Newel Knight, Jesse's family was poor throughout his youth. As a young man, he worked as a prospector and discovered the Humbug Mine in the Tintic Mining District near Eureka, Utah in 1886.