American factories in June were well on the way to recovery from the deleterious effects of a stronger dollar and plunge in oil prices. Then came Brexit.

The latest survey of purchasing managers by the Institute for Supply Management showed manufacturers were continuing to receive more orders and boost production last month after slumping for much of last year. The Tempe, Arizona-based group's factory index climbed in June to the highest level since February 2015, figures showed Friday.

The stronger-than-projected reading of 53.2, where anything greater than 50 signals growth, was based on responses received before U.K. voters decided to leave the European Union, which threw global financial markets into convulsion and caused the dollar to firm. While American factories have few customers in the U.K. and only a few more in the EU, it's the collateral damage from a rising dollar that will cause sales to slip globally and undercut the emerging improvement in U.S. consumer spending.