(CNN)Democratic Rep. Eddie Bernice Johnson of Texas announced her retirement Saturday afternoon after serving nearly 30 years in Congress, according to a statement from House Speaker Nancy Pelosi.

       Pelosi said in a statement Saturday that Johnson is "a dedicated and highly effective leader on behalf of Dallas area families and the entire nation for her thirty years in the Congress and nearly 50 years in public service."

       Johnson was the first Black woman elected to state public office from Dallas, according to Pelosi, as well as the first African American and woman to be the chair of the House Committee on Science, Space and Technology.

       "On behalf of her many friends in Congress, we thank the Chairwoman for her leadership for the people of Texas and all Americans, and wish her and her family, including her beloved son Kirk and grandchildren Kirk Jr, David and James, the best in their next steps," Pelosi said.

       The 30th Congressional District encompasses much of the city of Dallas and parts of Dallas County.