The index, which covers business conditions in the industrial belt of Indiana, Illinois and Michigan, fell 3.4 points to 49, as indexes for supplier deliveries, prices paid and production all fell to their lowest levels since 2009.
Numbers below 50 indicate a contraction and the headline index fell 1 point below that threshold.
The region's employment index dropped from 55.1 to 48.7, indicating a contraction in the size of the region's payrolls at manufacturing firms. The inventories index fell from 41 to 40.6.
The capital equipment index, which shows how much firms are investing in production equipment, rose from 112.2 to 114.2. The new orders index also bucked the trend, climbing from 53 to 53.2.