Online versions for some state's corporation laws are available from Findlaw and also through Lexis and Westlaw.
The Washington Business Corporation Act is codified in Title 23B of the Revised Code of Washington.
Although the United States Supreme Court has decided cases encompassing corporation law, the vast majority of precedent in this area comes from the state courts. These state court decisions are usually based on the statutes of that particular state. There is an entire digest topic devoted to "Corporations" in the West key numbering system. A researcher can either browse its topic analysis or use the Descriptive Word Index to find corporation cases using the applicable West digest.
Cases can also be found using online research. Both Lexis and Westlaw have databases devoted specifically to corporation law. These databases can be further limited to specific states, if that is desireable.
Finally, because most corporation cases involve interpreting a state's corporation act, cases can often be located in that state's annotated code.
Caveat: Even though most precedent on corporation law comes from the state, authority over certain ancillary issues may be federal. For example, securities law (regulating the registration and trading of stocks) is predominantly a federal issue.
As previously stated, corporation law is generally the province of the individual states. Today, most state's corporation statutes are based on the Model Business Corporation Act. Because of this, the commentary to the Model Act can be useful in interpreting the purpose behind the language used in a particular provision. The annotations to the Model Act also provide cases from the various adopting states. These case decisions can provide persuasive authority for statutory interpretation if the courts of the state you are researching has not addressed the issue.
Supplementary resources in our collection can be located by using our catalog of print and non-print resources. Using Library of Congress subject headings will help you get an overview of the materials available. Some suggested headings are: