Ogletree paired up with John Augenstein, who he defeated in the 2019 U.S. Amateur, earlier in the day for a foursome against GB&I's Euan Walker and Sandy Scott.
Craig Watson, the GB&I captain reflected on the switch in momentum at the end of day one when it looked like GB&I would take a four point lead into the final day until John Pak of team US managed to snatch the final two holes of his singles match against James Sugrue to grab victory and leave the score at 7-5.
After the four morning foursomes were shared, the home side won five of the eight afternoon singles for a 7-5 lead in the two-day biennial contest against America.
The U.S. improved to 37-9-1 overall in the Walker Cup.
But the loss of three holes in a row from the 11 proved to be pivotal as the Americans claimed their first point of the match.
Great Britain and Ireland captain Craig Watson consoles Alex Fitzpatrick after he lost his singles match
Casey started the final round one shot behind Bernd Ritthammer and Robert MacIntyre and played bogey-free for his 14th title on the European Tour. A hole later, they closed out their opponents, who missed their final four fairways.
A comeback by GB&I never looked on the cards and when John Augenstein defeated Thomas Plumb 4&3 the US were in an unassailable position at 13½-9½. England's Conor Gough, having just turned 17, looks a terrific prospect.
"I honestly thought that these guys would let their talent come to the surface." said Nathaniel Crosby, captain of the United States team. We came from behind to get one and they came from behind to get a halve.
"It could have been better but we knew the Americans were going to come back to us".
Stewart Hagestad, a member of the winning American team two years ago, then took his team into the lead with a resounding victory against Harry Hall by 5&3. On the other hand, the last time the US trailed after Day 1 and came back to win was 1963 at Turnberry. Only one player on either side has played a Walker Cup before - Hagestad was on the winning USA side two years ago at Los Angeles Country Club. "... Even though they're 0-2 going in, they might have the winning putt or the winning moment, and I put them in that spot for that very reason".
Walker, the losing finalist in The Amateur Championship in June, extended GB&I's lead after beating Steven Fisk, also rested for the morning foursomes, by two holes as well.