WASHINGTON — Sen. Cory Booker (D-N.J.) launched his presidential campaign on Friday, with a video in which he talked about the need for unity.

“I grew up knowing that the only way we could make change is when we come together,” Booker said in his announcement, which focused on his biography and experience.

Booker in 2013 became the first African-American senator from New Jersey, but he already had celebrity status for his years as mayor of Newark, a post he held from 2006.

Booker, a Yale Law School graduate and Rhodes scholar, focused his announcement video on those who helped him in his life and career, and how his father told him not to forget where he came from “or how many people had to sacrifice to get you where you are.” He noted that when he was a child, his parents tried to move the family into a neighborhood with great public schools, but realtors “wouldn’t sell us a home because of the color of our skin.” A group of white lawyers, inspired by the civil rights movement, stepped in to help and “they changed the course of my entire life.”

He also highlighted how he still lives in inner-city Newark, and is the only senator who lives in a low-income community.

The video does not make mention of President Donald Trump, but calls for a country “where we see the faces of our leaders on television and feel pride, not shame.”

Booker plans to travel to Iowa late next week for what his campaign is calling the “Iowa Rise” tour, starting with a stop in Mason City.

Booker is the fourth senator to launch a bid for the Democratic nomination. He joins Sen. Kamala Harris (D-Calif.), Sen. Kirsten Gillibrand (D-N.Y.), and Sen. Elizabeth Warren (D-Mass.). Others in the race include Rep. Tulsi Gabbard (D-Hawaii); South Bend, Ind., mayor Pete Buttigieg; and Julian Castro, a cabinet secretary during the Obama administration. John Delaney, a former congressman from Maryland, announced his campaign in 2017.

Booker has long courted donors and fundraisers in the entertainment community. Simon Kinberg hosted Booker at his home for an event in October to raise money for his Senate campaign and leadership PAC.