Best air travel from East Coast to Venice

There are a few nonstop flights from US airports to Venice, but not many and they tend to be seasonal. You are very unlikely to shorten your trip by routing via the east coast, even with one of these. Quickest will almost certainly be LAX nonstop to a European hub and connect there to Venice.

Agree with above
Get over the pond from LAX
At least you are then in Europe and have multiple options for getting to Venice if your flight is delayed or missed

Try to route thru Amsterdam, Munich, Frankfurt, Zurich, Rome
Avoid London and Paris

There are direct flights on United to Venice from IAD and EWR (seasonal) but you don’t want to risk getting stuck at either airport if there are any flight delays or cancellations
East coast weather is an issue year round- even spring and summer-thunderstorms delay flights all the time

ETA:
Always book with the actual airlines.

Use a search engine like Google Flights so you can see how long flights take and the typical hubs. I agree you'll not save much time stopping on the East Coast, and LAX has a plethora of choices for flights to Europe that will take much less time.

To save you time and hassle (but may not save you $) I suggest you look for open jaw/multi city tickets - LAX to Venice and Rome to LAX. On the way I'd pick a route that gets you to Europe first (e.g., LAX to Amsterdam or Frankfurt, then onward). Give yourself an extra day in Venice, at least, to explore and recover from jet lag.

From the West Coast the best option is always to fly directly to a European hub, bypassing the East Coast.
The Arctic route is shorter, and will give you a chance to see Greenland from above, a massively popular place these days.

Many choices from LAX to VCE via a European hub.
The most daily flights to VCE would be via the following hubs (all with 4 daily flights each way in winter, probably one or two more in summar):
London Heathrow (British Airways, an American Airlines partner)
Paris CDG (AirFrance, a Delta partner)
Frankfurt (Lufthansa, a United partner)
Rome FCO (ITA airways, a United partner)

With 2 or 3 daily flights in winter:
Amsterdam (KLM, a Delta partner)
Zurich (Swiss, a United partner)
Munich (Air Dolomiti, part of Lufthansa, a United partner)
Madrid (Iberia, an American Airlines partner)

If you select via London LHR or Paris CDG, try to have at least 2 hours (at the very minimum) to make the connections. Those two airports require the most time to change terminals.

Thank you everyone!!! I SO appreciate all your advice !!! looks like flying out of LA would be the best option… please keep posting, and I will consider every one’s advice… PS we are planning our tour either end of April/early May or early May….just looking at airfare cost options etc….

Check with Kayak or Google Flights to see the best options for your dates of travel.

There are a thousand ways to do it. The shortest, most convenient way will be a direct flight
Atlanta, Dallas, DC, NY (both), Philly, Toronto, Montreal all have regular ongoing direct flights to Venice. Probably more in summer.
There's lots of direct flights from Vancouver, LAX or SFO to Europe. Once in Europe, take a cheap flight to Venice.

Tools for you
Google Flights
Skyscanner
Flightsfrom

Do plan to arrive a day or two ahead of your tour start day! There is plenty to do in Venice and it gives you some Flex Time in case of travel delays.

Be aware there are some holidays in that time frame. April 25 is Liberation day. May 1st is their Labor Day. May 8 is Victory in Europe day. I'm not sure how big a deal May 8 is in Italy.