Place bread in a food processor, and pulse 6 times or until coarse bread crumbs measure about 1 1/2 cups.
Stir together crabmeat and next 7 ingredients. Shape mixture into 10 (2-ounce) patties; dredge in bread crumbs. Place patties on a baking sheet, cover, and chill at least 2 hours.
Cook crab cakes, in batches, in hot oil in a medium skillet over medium-high heat 3 to 4 minutes on each side or until golden. Serve with Watercress Vinaigrette.