Below is a list of organizations that sponsor conferences and festivals. Please let me know if I need to make any corrections or add an organization.
Washington, D.C.
Library of Congress National Book Festival, http://www.loc.gov/bookfest/
Literary Hill Bookfest, http://www.literaryhillbookfest.org/
Split this Rock, http://www.splitthisrock.org/programs
Maryland and beyond the Beltway
Artscape (Baltimore), http://www.artscape.org/
Baltimore Book Festival, http://www.baltimorebookfestival.com/
Baltimore Playwrights Festival, http://www.baltplayfest.org/
Bay to Ocean Writer’s Conference (Easton), http://www.baytoocean.com/
Bethesda Literary Festival, http://www.bethesda.org/specialevents/litfest/litfest.htm
Black Writer’s Guild of Maryland, Inc. (Baltimore), http://www.blackwritersguild.org/
City Lit Project (Baltimore), http://www.citylitproject.org/
Scott Fitzgerald Literary Conference (Rockville), http://cms.montgomerycollege.edu/edu/alt.aspx?id=28543
Frostburg State University Center for Creative Writing, http://www.frostburg.edu/cwcenter/
International Day of the Book (Kensington), http://www.dayofthebook.com/
Mid-Atlantic Fiction Writer’s Institute (formerly the Nora Roberts Writing Institute), http://nrwi.org/content/registration-conference-information
Virginia and Beyond the Beltway
Fall for the Book Festival (Fairfax), http://fallforthebook.org/
James River Writer’s Conference (Richmond), http://www.jamesriverwriters.org/what-we-do/programs/annual-conference
Virginia Festival of the Book (Charlottesville), http://vabook.org/