In Virginia, hundreds of veterans had their colon cancer screening tests invalidated after the results took months to arrive by mail. An Atlanta college student missed an academic trip to Ghana when their passport with two-day shipping took a month to show up. A bride in Texas had to rent a dress for her wedding after hers spent weeks stuck in a Houston postal facility.

Across the country, residents and businesses have been reporting widespread slowdowns in mail and package delivery by the U.S. Postal Service. The delays have become so persistent that members of Congress have gotten involved, urging the Postal Service to drastically correct course and raising concern about what impact the disruptions could have on mail-in ballots in the upcoming election.

The delays appear to largely stem from a new system the Postal Service began rolling out last fall that will eventually funnel all the nation’s letters and packages through […]