them as well, and soon many nations, including the United States, operated merchant ships and navy gunboats on the waterways of China. 1860–1900 During the 1860s and 1870s, American merchant ships were prominent on the lower Yangtze River, operating up to the deepwater port of Hankow inland. The added mission of anti-piracy patrols required U.S. naval and marine landing parties be put ashore several times to protect American interests. In 1874, the U.S. gunboat, , reached as far as Ichang, at the foot of the Yangtze gorges, from the sea. During this period, most US personnel found a tour in the Yangtze to be uneventful, as a major American shipping company had sold its interests to a Chinese firm, leaving the patrol with little to protect. However, as the stability of China began to deteriorate after 1890, the U.S. naval presence began to increase along the Yangtze. 20th century 1900–1920 In 1901, American-flagged merchant vessels returned to the Yangtze when Standard Oil Company placed a steam-powered tanker in service on the lower river. Within the decade, several small motorships began hauling kerosene, the principal petroleum product used in China for that company. At the same time, the United States Navy acquired four Spanish vessels (the gunboats , , , and ), which it had seized in the Philippines during the Spanish–American War. These vessels became the core of the Yangtze River patrol for the first dozen years of the 20th century, but they lacked the power to go beyond Ichang onto the more difficult stretches of the river. and were the first American gunboats built specifically for service on the Yangtze River. The Mare Island Naval Shipyard in Vallejo, California built them in 1913. The U.S. Navy then had them disassembled and shipped to China aboard the American steamer Mongolia. The Kiangnan Shipyard in Shanghai reassembled them and put them into service in 1914. Later in 1914, both vessels demonstrated their ability to handle the rapids of the upper river when they reached Chungking, which was more than from the sea, and then went further to Kiating on the Min River. In 1917, the U.S. entered World War I. The U.S. rendered the guns of Palos and Monocacy inoperable to protect Chinese neutrality. After China entered the war on the side of the Allies, the U.S. Navy reactivated the guns. In 1917, the first Standard Oil tanker reached Chungking, and