I'm assuming this has resurfaced in light of the announcement that Amtrak is launching nonstop DC-NY service (<a href="https://www.usatoday.com/story/travel/news/2019/07/25/amtrak-launching-nonstop-train-service-nyc-dc-in-september/1813463001/" rel="nofollow">https://www.usatoday.com/story/travel/news/2019/07/25/amtrak...</a>)<p>The new service will run one round trip daily (southbound in the morning, northbound in the evening) and take 2 hours, 35 minutes - which is what the OP says was running in 1969.