“OLD POUNDER,” THEY CALLED HIM—THE VERY FIRST NAVAJO SILVERSMITH. Yet Herrero Delgadito’s greatest legacy is measured in lives, not ounces: the scores of Navajo women and children he plucked out of slavery in 1864, the hundreds of exiles he risked everything to feed in 1865 and the thousands of people he helped lead back home in 1868.