Israel worked and owned farmland and was appointed justice of the peace for Gloucester County, New Jersey, in February 1775.
[3] After news came of the Battles of Lexington and Concord, Israel and his brothers William and Samuel enlisted as officers in the New Jersey State militia.
General John Thomas ordered Shreve to take some of the wounded to Sorel, at the juncture of the Richelieu and Saint Lawrence River.
[6] When General Charles Cornwallis led British troops out of Philadelphia, some of his men burned Shreve's house near Mount Holly, and Sir Henry Clinton offered a reward of 25 guineas for information on the soldiers' identities.
The next day General John Sullivan ordered his combined forces to Chemung, Pennsylvania, ten miles (16 km) west of Tioga Point, where they burned an Indian village and Israel's son, John, witnessed a skirmish with a retreating native tribe; a man standing next to him was killed by musket fire.
Both Israel and John Shreve returned to an army fort at Tioga while Sullivan led his command farther west.
Shreve's men waited at a bridge just west of the village of Springfield as Hessians under Lieutenant General Wilhelm, Baron von Knyphausen came from the east.
From January 1789 to June 1789, Shreve accompanied retired Continental Army colonel George Morgan to Spanish Louisiana Territory to survey the western bank of the Mississippi River.
Morgan, who was a land developer, received permission from the Spanish Ambassador to the United States, Don Diego de Gardoqui to establish a colony on the Mississippi River at Anse a la Graisse, located in present-day Missouri.
[17] On January 3, 1789, the expedition departed from Pittsburgh and traveled along the Ohio and Mississippi River until they reached Anse a la Graisse; a new town was demarcated and named New Madrid by Morgan.
[19] Instead of moving to New Madrid, Shreve decided to lease land in Fayette County, Pennsylvania, from General George Washington.