During the second phase of the Russian period (1785 to 1825), the Shelikhov-Golikov Company and later the Russian-American Company was organized and continued in the exploration of the lucrative north Pacific Ocean sea otter trade. During this time, they improved their treatment of the native people, skipping massacres for virtual enslavement and exploitation. The major portion of Alaska remained little known, and the Yup'ik of the Yukon-Kuskokwim delta were not strongly affected. The Russo-American Treaty of 1824 was signed in St. Petersburg between representatives of Russian Empire and the United States on April 17, 1824, and went into effect on January 12, 1825.