WASHINGTON—U.S. employers added a robust 379,000 jobs last month, the most since October and a sign that the economy is strengthening as confirmed viral cases drop, consumers spend more, and states and cities ease business restrictions. The February gain marked a sharp pickup from the 166,000 jobs that were added in January and a loss of 306,000 in December. Yet it represents just a fraction of the roughly 10 million jobs that were lost to the pandemic. The unemployment rate fell to 6.2 percent, the Labor Department said Friday in its monthly jobs report (pdf). A year into the pandemic that triggered a severe recession, economists are increasingly optimistic that hiring will pick up in the coming months as Americans seize the opportunity to once again travel, shop, attend sporting events and visit movie theaters and restaurants. Households as a whole have accumulated a huge pile of savings after having slashed …