Our Gale Encyclopedia of American Law, which is available online, has a section discussing the "Letter from a Birmingham Jail" that MLK wrote. You can either access it via the hyperlink above or on the library main page go to the Databases tab, click on "click here to access databases," and find the Gale Encyclopedia on the alphabetical list of databases.
If asked to log in, you do that with your LOLA# for the username and your birthdate formatted mmddyy for the password.