Roy Hodgson's side ended their week in Florida with a 0-0 draw against Honduras on Saturday which followed the 2-2 draw with Ecuador on Wednesday.
The training camp allowed them to acclimatise to the hot and humid conditions expected in South America and they have now touched down in Brazil after flying south from Fort Lauderdale.
"We had a good training camp and we're ready now," said Hart. "We got what we could out of it. We were always going to do that.
"We are working hard, we have worked hard every day on and off the field and we've given everything to be prepared.
"We feel good. We feel like we're doing the right things.
"It's great having Stevie [Gerrard] and Jordan [Henderson] and the various players screening us which is good, but I thought we looked dangerous going forward as well, which is a big positive.
"We feel like we've had a great three weeks together. We really feel like a team - a good strong English team going into a tournament with every chance to express ourselves and do well."