During the Battle of San Jacinto, he was seriously wounded and nearly died: Lonis, an infantry soldier, was shot in the breast early in the action, and fell in the tall grass, and lay there until after night, without being seen by his victorious comrades. He suffered terribly from his wound, and almost famished for water. He heard the battle receding from him; heard the shouts of victory, and the voices of his comrades near him, returning from the pursuit; but he was too weak to call for aid, and lay there wallowing about in his blood, almost delirious from the burning thirst that raged within. Sometimes he gave up all hope, and thought he must die for want of help with so many of his brave comrades near; but, then again, he would hear the sound of voices and hope would again revive, only to be disappointed as the sounds died away in the distance. It was now long after night, and he had been lying there since 4 o'clock, with a rifle ball in his breast, with not even enough strength to raise his head, but only to move it from side to side, and mutter low gurgling moans. At last he gave up all hope; he knew he could not survive until morning in this condition; his tongue was dry and thick, and he was almost choked with thirst; but, suddenly he heard a footstep near, which seemed to be passing the spot where he lay; his articulation was almost gone, but he uttered a faint moan. A few quick steps and Howard Baily and Frank Sparks bent over him. 'Wash Lonis' says Baily, 'the poor fellow, he is almost gone'. With a canteen of water he soon relieved the thirst of the wounded man. Baily being a strong man, carried him to camp in his arms, and by careful nursing, Washington Lonis recovered - Rangers and Pioneers of Texas (1884)
By 1851, Lonis and his wife, Margaret Cowan, were living in Brazoria County. They later moved to San Augustine County, before moving one last time to Guadalupe County where he died in 1882.
29° 34.412, -097° 56.113
San Geronimo Cemetery