Based on structural elements, the type of expository text that this excerpt from a 1917 Congressional address by President Woodrow Wilson exemplifies is persuasive. The purpose of a persuasive text is to to present a point of view and to convince a reader. A persuasive text can be an argument, exposition, discussion, review or even an advertisement. In this case, the aim of the congressional address is to convince the nation to enter the war with Germany.