Every law in the country begins somewhere, and the road from idea to law has many stops. A federal law follows this road. Every new law starts out as an idea. A bill is a plan for a new law, or a change to an old law. People can ask their lawmakers to start a new law, and a bill can be started by a member of the House or Senate. Those lawmakers belong to Congress, the part of the national government that makes laws. Congress has two parts: the House of Representatives and the Senate.

After a bill is introduced, it goes to a committee of lawmakers who study it and can change it. House committees often begin with a public hearing, where members hear witnesses who represent different viewpoints on the bill. After the hearings, a House committee holds a "mark-up" session. Members study the viewpoints, may offer amendments, and vote to accept or reject the changes. A committee can report a bill, with or without amendments, or table it, which means no further action on it will happen.

After a committee releases a bill, the bill is put on a calendar to be voted on, debated or amended. In the House, debate on a bill may be governed by a "rule", which is itself a simple resolution that the House must pass. A rule sets out the particulars of debate for a specific bill. Debate time on a House bill is normally divided between supporters and opponents, and each side gives time to the members who want to speak. Members debate amendments to a bill and then vote on them. House votes can be taken by an electronic voting system that records each member's response.

A bill has to pass both the House and the Senate before the president can sign it. When the House passes a bill, it goes to the Senate, which studies and votes on it too. If the Senate changes a bill, the House has to look at the changes, and the two sides must work out their differences. If the Senate and House pass different versions, a conference committee of members from both can settle the differences and report one identical bill back for a vote in each house. Only the House can start a bill about taxes or raising money, though the Senate can still make changes to it.

After both houses pass a bill in identical form, it is called "enrolled" and is sent to the president. The Constitution gives the president 10 days, not counting Sundays, to act on a bill. The president may sign an enrolled bill into law, veto it and return it to Congress, let it become law without a signature, or at the end of a session pocket-veto it. Article I, section 7 of the Constitution gives the president the power to veto bills passed by Congress.

In a regular veto, the president returns the unsigned bill to the house of Congress where it began, within 10 days, usually with a memorandum of disapproval or a veto message. If the president vetoes a bill, Congress can sometimes vote to override the veto and make it a law. To override a veto, Congress needs a two-thirds vote in each house. A pocket veto cannot be overridden by Congress. George Washington issued the first regular veto on April 5, 1792. The first time Congress overrode a veto was March 3, 1845, when it overrode John Tyler's veto of S. 66. Even the threat of a veto can change the content of legislation long before a bill reaches the president.

After the president signs a bill into law, it goes to the Office of the Federal Register, which assigns a law number and prepares it for publication as a slip law. Public laws affect society as a whole, and most laws passed by Congress are public laws.

The U.S. government has three branches: legislative, executive and judicial. The system of checks and balances lets each branch respond to the actions of the others. The Supreme Court can overturn laws that go against the Constitution. Judicial review is the power of the courts to examine the actions of the legislative, executive and administrative arms of government and decide whether they are consistent with the constitution. Nothing stated in the Constitution gave the Court the specific power of judicial review. Judicial review was not confirmed until 1803, when Chief Justice John Marshall invoked it in Marbury v. Madison.

Cities and towns can make laws too. Local laws are often called ordinances, and a city council or county commission can pass them. Local ordinances often follow set steps: public notice, a public hearing, a required number of votes, and publication of the final ordinance. States have their own steps. In California, a bill starts when a person or group persuades a member of the Legislature to author it. After a bill passes its house of origin, it goes to the second house and passes through the committee process all over again. In California, the governor has 12 days to sign, approve without signing, or veto a bill.

The Constitution has its own history. In 1787, leaders called the Framers met in Philadelphia and wrote the U.S. Constitution. The Articles of Confederation, which came before the Constitution, essentially operated as a treaty between thirteen independent sovereigns. At the 1787 convention, the idea of amending the Articles of Confederation was discarded and the assembly set about drawing up a new scheme of government. Edmund Randolph offered the Virginia plan, a bicameral legislature with each state's representation based on its population or wealth. William Paterson proposed the New Jersey plan, which provided for equal representation in Congress. The Great Compromise gave each state equal seats in the Senate and seats in the House based on population. The Great Compromise was approved on July 16, 1787.

Words to know

• committee: lawmaker study group
• amendments: changes
• enrolled: final passed copy
• veto: say no
• override: overrule a veto
• ordinances: local laws