There were also professional recruiters, or "agents," employed by mining and shipping companies, who encouraged Finns to move to the United States. More than 90% of the Finnish immigrants lived in urban centers. This activity was frowned upon by the authorities of the Grand Duchy, and was mostly done in secret. It was eventually brought to an end in the late 1880s by legislation in the U.S., but the decade still saw a 12-fold increase in the number of Finnish migrants compared to the previous decade, as 36,000 Finns left their home country for North America.