Ireland's three-time major champion Padraig Harrington was the highest-profile player to miss out on qualification for the U.S. Open after an agonising finish at Walton Heath.
Johnston, born just a few miles from the Surrey golf club, delighted local crowds by clinching his spot in what will be his debut tournament in America and just his second major championship appearance. The 27-year-old is continuing to ride the wave that brought him a maiden European Tour title in Spain last month and a top 10 finish in his home event, the BMW PGA Championship, on Sunday.
Slattery and Baldwin both have previous U.S. Open experience having teed up at the Olympic Club in 2012. Slattery carded two rounds of 69 and Baldwin two rounds of 70 to qualify.
Four-time European Tour winner Bourdy had hinted at having rediscovered his best form with strong finishes in Ireland and at Wentworth in the last two weeks, and the 34-year-old followed a 5-under-par 67 around the New Course in the morning with a 4-under-par 68 around the Old Course to head the 13 players earning spots at the U.S. Open, which begins on June 16.
Lundberg, a three-time European Tour winner, will make his major Championship debut after finishing on 7-under-par overall in cold and blustery conditions in Surrey.