The differing jurisdictions within the US have varying statues of limitations of certain laws. Where can statutes of limitations be found (according to the law's jurisdiction - Federal, State, County, City, etc...) for each particular law?
The authority that established the offense is generally the same authority that establishes a statute of limitations, if any. Federal statutes of limitations are established by Congress, so they're found in federal statutory law -- for example, you can find the general felony statute of limitations at 18 U.S.C. § 3282, but Congress can set different statutes for different offenses.
State statutes of limitations are similarly set by the state's legislative authorities. For example, California's statutes of limitations are enacted by the California legislature; a sample of them can be found here.
Municipalities (cities) in the US often don't have the power to establish criminal offenses. If they do, their power is governed by state law, so their state legislatures might have already established applicable statutes of limitations. In Colorado, for example, the City of Denver has the power to establish municipal offenses, which are misdemeanors, which it does in Chapter 38, Denver Code of Ordinances, but Colorado law establishes an 18 month statute of limitations for all misdemeanors (Colorado R.S. § 16-5-401).
Thay varies a good deal by jurisdiction. Some laws include their own ataturw od limitations, that is how long after an event a prosecution or legal actio may be started. Some jurisdictions have a single law with a list or table giving the limitign period for each of several types of laws. Some have one law giving limnitations for felonies, another for misdemeanors, yet another for torts, perhaps another for contract actions.