After the President signs a bill into law,
it is delivered to the Office of the Federal Register (OFR),
Official Text of Public Laws
You can find Public Laws starting with the 104th Congress on the GPO Access web site.
They are also available in print as slip laws and the U.S. Statutes at Large.
The U.S. National Archives and Records Administration
1-86-NARA-NARA or 1-866-272-6272