The ISM index dropped to 50.9 in July from 55.3 in June, according to the Institute of Supply Management’s monthly manufacturing report on business.
Economists polled by Thomson Reuters predicted the index would rise to 54.9.
Northwest Nazarene University, an Idaho private Christian college, had its ratings outlook revised to positive.
Munis should do "relatively well" this month, as investors will "focus on heavy summer redemptions; tax-exempt supply should remain healthy but is unlikely to overwhelm," said Barclays strategists.
The Manhattan-based Ivy League university reached a settlement with the federal government last year. It is selling $487 million of bonds this month.
"The rates market has started to turn from the upper end of the trading range this week," Barclays strategists wrote, but with the war with Iran still driving the market, nothing is certain.
Changes in federal funding are sharpening the focus on how the states will be responding to disaster relief, running social programs and budget planning.
The defendants include many of the largest municipal bond underwriters.