sentences:  During the summer of 1776, he secretly helped the Americans by privately delivering five tons of gunpowder from the king's stores to Captain George Gibson and Lieutenant Linn of the Virginia Council of Defense.The gunpowder moved up the Mississippi under the protection of the flag of Spain and was used to thwart British plans to capture Fort Pitt.From June 17, 1777, to December 10, 1782, Unzaga served as Captain General of Venezuela.