Final answer:
The only branch of government under the new document is the Legislative Branch, which consists of Congress - the House of Representatives and the Senate.
Step-by-step explanation:
The only branch of government under the new document is the Legislative Branch. According to Article 1 of the United States Constitution, only Congress has the power to make laws, and it consists of the House of Representatives and the Senate. The legislative branch was created to represent the people and ensure that laws are fair and representative of the nation's needs.