Examples of Annexation Pacific Northwest and California, United States. In 1844 onwards, United States of America attempted to merge disputed parts of the Pacific Northwest of North America into their country. James Knox Polk, the 11th President of the United States, used as a successful campaign slogan "54-40 or fight!", commenting on the latitude of the western portion of the border between Canada and the United States, a border which was later officially set at the 49th parallel.