Yangtze Patrol The Yangtze Patrol , from 1854 to 1941 , was a prolonged naval operation to protect American interests in the Yangtze River ' s treaty port s . Initially the patrol was carried out by ships of the United States Navy ' s East India and Asiatic Squadron s . In 1922 , the " YangPat " was established as a formal component and assigned to the Asiatic Fleet . Under the " unequal treaties " , the United States , Japan , and various European powers were allowed to cruise China ' s rivers . They also patrolled coastal waters , protecting their citizens , their property , and their religious missions . The Yangtze is China ' s longest river , and very important to commerce . Ocean - going vessels were able to proceed as far upstream as the cities of Wuhan . This squadron - sized unit cruised the waters of the Yangtze as far inland as Chungking , more than from the sea , and occasionally far beyond . Operations . 19th century . As a result of the " unequal treaties " imposed on China by Great Britain after the Opium Wars , China was opened to foreign trade at a number of locations known as " treaty ports " where foreigners were permitted to live and conduct business . Also created by the treaties was the doctrine of extraterritoriality , a system whereby citizens of foreign countries living in China were subject to the laws of their home country , not those of China . Most favored nation treatment under the treaties assured other countries of the privileges afforded Great Britain , and soon many nations , including the United States , operated merchant ships and navy gunboats on the waterways of China . During the 1860s and 1870s , American merchant ships were prominent on the lower Yangtze , 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 , 975 miles 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 . In 1901 , American - flagged merchant vessels returned to the Yangtze when Standard Oil Company placed a steam 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 Navy acquired three Spanish - built 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 . The 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 a pattern of American commerce on the river began to emerge . On January 17 , 1918 , armed Chinese men attacked " Monocacy " and she was forced to return fire with her 6 - pounder gun . Passenger and cargo service by American - flag ships began in 1920 with the Robert Dollar Line and the American West China Company . They were followed in 1923 by the Yangtze River Steamship Company , which stayed on the river until 1935 , long after the other American passenger - cargo ships were gone . In the early 1920s , the patrol found itself fighting the forces of deadly warlords and ruthless bandits . To accommodate its increased responsibilities on the river , the Navy constructed six new gunboats in Shanghai in 1926 - 1927 and commissioned in 1928 to replace four craft originally seized from Spain during the Spanish - American War that had been patrolling since 1903 . All were capable of reaching Chungking at high water , and two year - round . and were the largest , and next in size , and and the smallest . These vessels gave the navy the capability it needed at a time when operational requirements were growing rapidly . In the late 1920s , Chiang Kai - shek and the Northern Expedition created a volatile military situation for the patrol along the Yangtze . During the early - 1930s , National Revolutionary Army took control of much of the north bank of the middle river . The climax of hostilities occurred in 1937 with the Rape of Nanking and the sinking of " Panay " by the Japanese . The USS " Panay " incident was the first loss of a US Navy vessel in the conflict which would soon become World War II . After the Japanese took control of much of the middle and lower Yangtze , American gunboats entered into a period of frustrating inactivity and impotence . Just prior to the attack on Pearl Harbor , most of the ships on the Yangtze River Patrol were brought out of China , with only the smallest gunboats , " Wake " ( the renamed " Guam " ) and " Tutuila " remaining behind . " Wake " , at Shanghai , was subsequently captured by the Japanese . " Tutuila " , at Chungking , was turned over to the Chinese . When the other gunboats reached Manila , the Yangtze River Patrol was formally dissolved when , on 5 December 1941 , Rear Admiral Glassford sent the message , " COMYANGPAT DISSOLVED " . Subsequently , the evacuated ships were all scuttled , or captured with their crews and imprisoned by the Japanese , after the fall of Corregidor in mid - 1942 . " Luzon " was later salvaged and used by the Japanese . " USS Asheville ( PG - 21 ) " was sunk in battle 3 March 1942 and was scuttled on 2 May . During different periods of time , Naval and Marine Corps personnel who were in the patrol may have been eligible for either the Yangtze Service Medal or the China Service Medal . Some patrols on the river were resumed in 1945 , and included — among others — the destroyer and light cruiser . When the Chinese Civil War reached the Yangtze Valley , this activity ended . Popular culture . USS " San Pablo " , the vessel in Richard McKenna ' s well - known novel " The Sand Pebbles " ( 1962 ) , set in 1926 , was modeled on the , a 31 - year old vessel originally captured from Spain . McKenna served aboard one of the newer river gunboats a decade after the time frame of his novel , as did William Lederer , the author of " The Ugly American " ( 1958 ) . The film " The Sand Pebbles " was based on the book . New York Times and Wall Street Journal best selling author , W . E . B . Griffin places the main character of his book " Semper Fi " within the Yangtze River Patrol . The opening chapters of this book provide an in depth illustration of both the mission and everyday life of United States Marines assigned to the Yangtze Patrol during the 1930s . Kemp Tolley , an officer who served as executive officer of the " Tutuila " in the 1930s , wrote a well - received history , " Yangtze Patrol " . Sergeant Bobby Shaftoe of the United States Marine Corps is a protagonist and POV character in Neal Stephenson ' s epic Cryptonomicon . He opens the novel as a member of the Yangtze River Patrol . References . " Most information came from the United States Navy and is in the public domain . "