What did President John Tyler do?

John Tyler was the tenth president of the United States of America, from 1841 to 1845. He was sworn in to the office unexpectedly after the death of the serving president, President William Henry Harrison.
In 1842, President Tyler authorized the Webster-Ashburton Treaty with Great Britain, which settled a number of border disputes between the United States and British colonies to the north.
In 1844 President Tyler ratified the Treaty of Wanghia, which secured for the United States the rights to trade in Chinese ports. Under the treaty, the United States was also granted the status of a favored nation, meaning that the United States would be given the same benefits as were afforded to the British.
In 1845, President Tyler signed a resolution which permitted the annexation of the Republic of Texas into the United States. This annexation led to a war between the United States and Mexico in 1846.