Subsequently, Russian explorers and settlers continued to establish trading posts in Alaska, the Aleutian Islands, British Columbia, Washington (state), Oregon and as far south as Fort Ross in northern California. Fort Ross, some 50 miles north of San Francisco was founded in 1812 and closed in 1841.
The peak population of the Russian colonies was about 40,000 although most of these were aborigines.
The colony was never very profitable, because of the costs of transportation. At the instigation of Secretary of State William Seward, the United States Senate approved the purchase of Alaska from Russia for $7,200,000 on April 9, 1867.
In 1818, Dr. Schaeffer, a Russian entrepreneur occupied Kauai and negotiated a treaty of protection with King Kaumualii of Hawaii but the Russian emperor refused to ratify the treaty.
In Russia and even in its predecessor, the Soviet Union, there has been speculation in the Russian mass media that Alaska was not, in fact, sold, but was instead leased to the USA for 99 or 150 years and has to be returned to Russia. It may be explained in part by the notion that soon after the 1917 revolution in Russia all the secret tsarist international agreements were officially denounced and declared void by the new government.
See History of Russia and European colonization of the Americas.