WASHINGTON (AFP) - The United States manufacturing sector hit the one-year mark in its recovery from the slump brought on by the Covid-19 pandemic, but factories struggled with snarled supply chains, an industry survey said on Tuesday. The Institute for Supply Management (ISM) reported that its manufacturing index last month rose to 61.2 per cent from April, slightly more than expected and above the 50 per cent mark indicating expansion for the 12th straight month. Manufacturers responding to the survey were broadly optimistic, but complained of issues getting inputs and employees - concerns shared by businesses across the US economy as vaccines help them bounce back from the worst of the pandemic disruptions. "Record backlog, customer inventories and raw material lead times are being reported. The manufacturing recovery has transitioned from first addressing demand headwinds, to now overcoming labour obstacles across the entire value chain," ISM survey chair Timothy Fiore said. The supplier deliveries index rose nearly four percentage points to 78.8 per cent, the highest since April 1974, indicating longer delivery times. Employment dropped to 50.9 per cent as firms struggled to f...