More than 50 million Americans have filed for unemployment since the start of the pandemic, overwhelming some states. WSJ visits an unemployment processing event in Ardmore, Okla., to hear from some of the people waiting to get help with their claims. Photo: Benjamin Lindsey An increasing number of workers were unemployed for more than three months in July, a signal that the coronavirus pandemic is likely to have a lasting economic impact on many people. The number who were unemployed between 15 and 26 weeks rose by a seasonally adjusted 4.6 million to 6.5 million people last month, according to the Labor Department. The July reading is the highest on record for the category in data going back to 1948, and it is nearly double the prior peak, set in 2009 at the end of the last recession. …