Assigned to the Asiatic Squadron, Monocacy remained there until 1903, a period of service so long that the light-draft gunboat was given the nickname "Jinricksha of the Navy".

After patrol duty through 1867, Monocacy joined her squadron in representing the U.S. Government at the opening of the ports of Osaka and Hyōgo, Japan, 1 January 1868.

In December, she surveyed the Inland Sea between Nagasaki and Osaka to locate appropriate sites for lighthouses, another step in the realization of American commercial trade with isolationist Japan.

After Korean shore batteries attacked screw tug USS Palos near Chemulpo, a landing party of 576 sailors and 110 marines stormed a series of forts along the Salee River on 10 June, losing three killed and seven wounded.

On 7 October 1884, while at Fuzhou, China, Captain of the Afterguard William H. Belpitt rescued a Chinese man from drowning, for which he was awarded the Medal of Honor.