All Morgan and Peace dollars are VAM's. However, it is very rare that a die crack warrants attribution in and of itself. That is because they are very common since 130+ tons of pressure is required to strike the coin. If you want to determine the exact VAM for your Morgan, you should visit VAMWorld and compare your coin to the descriptions for the '21 Philly. Chris
To narrow it down a little, the reverse is a D1 reverse (17 berries on wreath). As has been said, the cracks alone won't be the main diagnostics for any given VAM until they become larger die breaks, as it is quite common for cracks to develop in the peripheral lettering. If you really want some frustration, look at the area above the eagle's right (viewer's left) foot for fine, random die scratches. These were put there at the mint on many dies that had poor detail in that area, and can often be attributed. It'll take you a Long Time to attribute (they slow me down a lot when going through batches of coins) and won't be worth a premium, anyway.
On another coin, I might poke around VW and help. But there were zillions of 21-p Morgans, and there are more than a hundred VAMS. Good luck!
