Americans went to the polls on Tuesday to choose the next president of the United States, deciding whether Senator Barack Obama or Senator John McCain was better suited to guide the nation through an economic crisis at home and two wars abroad.In voting booths in every corner of the land, the people were collectively writing the ending to a political saga that has been unfolding for nearly two years, during a tumultuous, uncertain period of American history in which record numbers of people expressed concerns that the country was heading down the wrong track.