The new five year plan, FY24-29:
Page 45
https://www.amtrak.com/content/dam/projects/dotcom/english/public/documents/corporate/businessplanning/Amtrak-Service-Asset-Line-Plans-FY24-29.pdf
It will tell you if multiple trains (a transfer) are required for your itinerary, but the midday weekday Northeast trains (including 95 and 2155, if you're leaving Stamford around 10am) will all carry through to at least Washington, so you can stay on through New York.
Leaving from Washington...