Former Newark Mayor and U.S. Sen. Cory Booker announced on Twitter this morning that he was running for president of the United States.

Booker's announcement on the first day of Black History Month comes as no surprise. The 49-year old senator's run was years in the making and he has recently stepped up his travel to early primary states, including in Iowa, New Hampshire and South Carolina.

Booker enters a growing field of Democrats vying for the 2020 nomination. Among those who have previously announced include fellow senators Elizabeth Warren of Massachusetts, Kamala Harris of California and Kirsten Gillibrand of New York.

Sign Up for E-News

In his Twitter announcement, Booker returns to a theme that he once used with great fanfare during a 2009 State of the City address based on Maya Anjelou's poem, "Still I rise," in which he declared, "Newark will rise."

"Together, America, we will rise," Booker says in his video announcement.

In the video, Booker references his youth, when he says his parents tried to move the family to a neighborhood with great public schools, but Realtors wouldn't sell his parents a home because of the color of their skin.

"A group of white lawyers who had watched the courage of civil rights activists were inspired to help black families in their own community, including mine," Booker said. Booker's family eventually moved into Harrington Park, a predominantly white suburb in Bergen County.

“The history of our nation is defined by collective action; by interwoven destinies of slaves and abolitionists; of those born here and those who chose America as home; of those who took up arms to defend our country, and those who linked arms to challenge and change it,” Booker said.

More to come