Who is Lem Lewis from The Glory Field and what is their importance?

Lem Lewis is born in 1847. Lem is the oldest son of Moses and Saran Lewis. He is the nephew of Joshua Lewis. When Lem is seventeen, he runs away from Live Oaks plantation with his uncle Joshua. After he is brought back to Live Oaks and tied to a tree, Joshua comes back in search of him and Lem, Josh, and Lizzy all escape. Lem Lewis joins the Union army and fights for the North in the Civil War. When Lem is killed in the fighting, his body is returned to Live Oaks and buried in an unmarked grave somewhere in the Glory Field. Old Master Lewis will not permit Lem's body to be buried on Live Oaks because Lem ran away.