For the first time in history, three Black women will serve simultaneously in the U.S. Senate when Illinois Lt. Gov. Juliana Stratton takes office in January.Why it matters: It took over 235 years for two Black women to serve in the U.S. Senate at the same time. Two years later, that number will grow to three.Driving the news: Stratton won election to the U.S. Senate on Tuesday, defeating Republican Don Tracy, per AP.She'll join Sens.