Is this every federal law?

[True Federalist (진정한 연방 주의자)]

No.

If you want every Federal Law, you have to go to the United States Statutes at Large.  However,  those laws that act on a continuing basis of general interest are classified to the United States Code.  So budget bills, laws that tell the executive to name some federal building after someone, etc., don't get put in the code.

There is also the Code of Federal Regulations, the Harmonized Tarriff Schedule, and the Treaties and Other International Acts Series.

[True Federalist (진정한 연방 주의자)]

Depends on the law.  Some portions of the Code are what are known as positive law and so amendments to those portions of the law are made by directly citing the relevant code. Others aren't so it gets more complicated for those because then the US Code only serves as an index into the real law and so to amend those would require amending the underlying Statute at Law, not the US Code directly.  Generally, the amending law tries to be helpful and assign a suggested position in the US Code in such cases, but it isn't an absolute requirement.

[True Federalist (진정한 연방 주의자)]

It all depends on what the law is trying to do and where it would go in the code.  In theory, they could even create new titles, but except for merging Title 34, Navy with Title 10, Army and Air Force to form Title 10, Armed Forces in 1956, they've stuck with the 50 titles established when the United States Code was first published in 1926.

[True Federalist (진정한 연방 주의자)]

Finally found a site that has all of the old Statutes at Law

http://constitution.org/uslaw/sal/sal.htm

The other two links provide no coverage for 1876-1950, this one covers up till early 2013.

[True Federalist (진정한 연방 주의자)]

Hmmm I wonder what the oldest statute is

The very first act passed by Congress under the Constitution, concerning the administration of oaths of office for various offices, is still on the books, codified in the U.S. Code in various places depending upon the office. I doubt if any statues are on the books from the Confederation, tho I suppose it would be possible for a land title case in the old Northwest or Southwest Territories to make use of such an old law.