There were lots of “turning points”, Coral sea being one of them. But for me, still, the biggest one was Midway. All we really had to do was make this a “time consuming” war, giving us the time to beat the axis with our manufacturing might. Once the timeline got extended, neither Germany nor Japan had a chance.
And they knew they had to win fast. Actually, not “win”, but get us to negotiate a peace.
And thank God for Winston Churchill, who went against popular (and political) sentiment and refused to negotiate with Hitler for a truce when they seemed just about down for the count.
I cannot imagine how much harder our task would have been (in Europe AND the Pacific), if Britain had taken themselves out of the fight.