Southern Pacific FP7 6450 with F7B and F7A leads train 54 the Sacramento-Los Angeles "Sacramento Daylight" at Bakersfield, California on April 24, 1964. Photo by Al Chione, from my collection.
In the years after World War II Southern Pacific went from being the most bullish railroad on passenger service to one of its biggest detractors. It continually downgraded service until Amtrak took over what remained.