Tour captain Rory Best and his fellow try scorer Bob Casey both said 'frustrating' when asked to describe the match afterwards, and that is how it played out as the Eddie O'Sullivan-coached Eagles made it a tough afternoon's work for the tourists.
A ten-point second half spurt, which included an Ata Malifa drop goal and a converted try from Roland Suniula, saw the home side make a real game of it at 20-10.
But, following up on earlier touchdowns from Casey and Ian Whitten and a penalty try, Ireland skipper Best closed out the result with a 70th minute try.
Bidding to improve on last weekend's showing against Canada, Kidney retained the same players in his matchday squad. There was one team change with Mike Ross preferred to Tom Court in the front row.
O'Sullivan's first game in charge saw him field a very inexperienced USA side, including six debutants in the starting line-up and a new captain in scrum half Mike Petri.
Although, as a collective they failed to fire, there were some notable individual displays from Ireland.
Ian Keatley kicked well out of hand and broke forward to set up Whitten's try, while Mick O'Driscoll and Casey had solid shifts in the second row and Tony Buckley and replacement Eoin Reddan also had some eye-catching moments.
With the tour and the upcoming Churchill Cup being used to build towards the 2011 Rugby World Cup, a total of nine players made their Test debuts over the past two weekends - Whitten, Ross, Keatley, Darren Cave, Ian Dowling, John Muldoon, Niall Ronan, Ryan Caldwell and Denis Hurley.
Kidney insisted afterwards that the players will be better for the experience of playing back-to-back Tests, even if the performance level was lower than expected.
"It was obviously a very poor game and there were a lot of mistakes in it," he said.
"We need to be honest with ourselves about how that went.
"While they trained well during the week, they have to front up week in, week out for international rugby and, while I'm not saying they didn't do that, we have a lot to learn.
"Having said that, we didn't get too euphoric about the Six Nations and we're not going to get too despondent now after these game.
"We said we'd do both tours - this and the Churchill Cup - to see what players were coming through.
"A few of the lads here will stay on, a few lads will go home and the pre-season will be massively important to them."
For the first time, the Irish senior management will take charge of Ireland 'A for the Churchill Cup tournament, which begins for the men in green on Wednesday week against Canada in Glendale, Colorado.
It is all part of a process which should see Ireland peak for the Rugby World Cup, and Kidney said that time will obviously be a factor in these newcomers pushing for inclusion in that squad.
He also emphasised the important of their pre-season work in the lead-up to New Zealand 2011.
"For the lads that came out here, there's a real chance for them to stake a claim for the senior side for November.
"For us, it's only half way through what is effectively a five-game tour and we'll look forward to the rest of it, and hopefully we'll get better games out of it than we had today.
"The players' pre-season this year, and their pre-season next year, is what's going to have to carry us through to the World Cup.
"We need to be at our optimum in two-and-a-half years' time and that takes time.
"It's like the Olympics - people train for four years for the Olympics, we have two-and-a-half years to the World Cup."
Kidney's opposite number Eddie O'Sullivan, who guided Ireland to three Triple Crowns between 2004 and 2007, was very pleased with the efforts of his American players.
Despite missing the likes of last year's captain Todd Clever and Biarritz flyer Taku Ngwenya, the Eagles really raised their game against Ireland.
Focusing on the performance rather than the result, O'Sullivan said: "It was a good hit-out for us. We did well overall, we made some mistakes and got punished for them.
"But for our first day out, I was pleased with the overall performance.
"Our lineout didn't function a lot of the time but the scrum did well and our defence was pretty strong throughout.
"Had we kicked our penalties and held out in other defensive situations, it might have been a tighter game.
"It's a good foundation for us, this is the start of a busy six or seven weeks which culminates with two World Cup qualifiers against Canada."
Asked what his players can improve on ahead of next weekend's clash with Wales, he said: "We didn't take our penalties, they're the things you learn from.
"If we can tidy up our lineout, take our penalties, we'll be in good shape for the games ahead."