After reporting sluggish progress last month, U.S. officials announce that the stretch of barriers has grown to 145 miles. ...Whether the new fencing slows illegal immigration remains to be seen, but the project is a milestone in another way. Once limited mainly to cities, fencing along the 1,952-mile border is now going up in rural areas, where much of the illegal immigration traffic has shifted in recent years. Fleets of tractor-trailers loaded with fence posts and steel tubing have been crossing remote highways and deserts. Crews of National Guard troops spend hours welding raw materials under tarps. In some areas,...