On September 26, 2008 Omega gave birth to its 935th graduate chapter. Theta Mu Mu holds the distinction as Baltimore County, Maryland's first graduate chapter of the Fraternity. Though officially established in 2008, the efforts to charter the chapter began more than a year earlier. Eight brothers who resided in the Baltimore-Metropolitan area began meeting monthly at the homes of Evan Murray (1990 Eta Gamma), and James Pierce (1985 Pi). The other organizers included: S.D. Rhawli F. Coakley (1989 Pi), Jeff Givens (1987 Omega Lambda), Derrick Green (1990 Gamma), Edwin T. Johnson (1991 Pi), Robert Smith (1987 Eta Lambda), and Eric M. West (2001 Pi Omega). The organizers agreed that there was a significant population in Baltimore County, Maryland that would benefit from the presence of a graduate Omega chapter.
Since its establishment, Theta Mu Mu has called Omega men to task. The first meeting was held at Milford Mill Academy on October 9, 2008. More than 50 Brothers were in attendance. Leadership of the chapter includes: David Patterson (1990 Delta Beta) Basileus, Evan Murray (1990 Eta Gamma) Vice-Basileus, Dwayne Johnson (2002 Pi Omega) Keeper of Finance, Eric M. West (2001 Pi Omega) Keeper of Records and Seal, Ermon Hervey (2005 Rho Alpha Alpha) Chaplain, and Keith Winslow (2004 Pi Omega) Keeper of Peace.
Theta Mu Mu immediately began the work of Omega. On the historic November 4th, 2008 election, members of the chapter assisted Baltimore County voters with transportation to and from the polls. The Achievement Week Program was observed, and included cleaning-up the graves sites of Bishop Love. Theta Mu Mu partnered with Pi Omega Chapter and fed the area homeless during Thanksgiving and Christmas holidays. On January 19th, 2009 Theta Mu Mu Brothers represented the fraternity participating in Baltimore City's Martin Luther King, Jr. Day Parade. The following day, chapter members were among the volunteers in the historic inauguration of President Barack Obama. On President's Day, Theta Mu Mu participated in the Youth Leadership Teen Summit sponsored by Congressman Elijah Cummings. In its infancy the new chapter set a tremendous pace and believes that it will continue to impact the region in a positive manner. The chapter's February 2009 meeting was hosted by the undergraduate Brothers of Iota Epsilon Chapter and held on Towson University campus.