institution like this. >> reporter: she has a reputation for sometimes being intimidating. making male colleagues c s cowe. >> i think that when women are persistent and insistent, we're viewed as tough. now, i view it as just being effective. >> reporter: one of her proudest achievements legislation giving women equal pay for equal work. the first bill signed by the first black president. >> he said this pen is yours. >> reporter: now, it's the end of the obama and the mikulski eras and the trailblazing senator walked out the door, dropping important pearls of wisdoms. >> always listen to the people. they really do have the best ideas. >> reporter: dana bash, cnn, capitol hill. >> she's going to be missed in congress. she's been around so long. i remember when i was a budding young reporter, maybe even an intern and going out and