Cory Booker (Kena Betancur/Getty Images)

Newark, N.J., Mayor Cory Booker won the Democratic primary in New Jersey's Senate race on Tuesday, putting him on a path to become a U.S. senator if he wins an Oct. 16 special election against Republican Steve Lonegan. If he's chosen to complete the remaining 15 months of the term of the late Sen. Frank Lautenberg, who died earlier this year, he'll become the eighth member of what is still a pretty small club: that of African-American senators.

From Hiram Revels to Tim Scott, they're a diverse group. Read a little about the politicians who paved the way, and how they made their way to the U.S. Capitol.

Hiram Revels

Hiram Revels (MPI/Getty Images)

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This Civil War veteran served only one year in the Senate, but it was a significant one. Revels, a Methodist minister born in 1827 who studied at Knox College in Illinois, became the United States' first African-American senator in 1870. The Mississippi Legislature sent him to the U.S. Senate during Reconstruction. Once there, the Republican became an outspoken opponent of racial segregation, not to mention a living example of it.

Blanche K. Bruce

Blanche K. Bruce (Time Life Pictures/Getty Images)

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How does someone born into slavery in 1841 end up in the halls of Congress? In Bruce's case, the interim involved an escape up North and a career in education and politics. He was elected by the Mississippi Legislature to the U.S. Senate in 1874 as a Republican and served from 1875 to 1881. You can see a photo of him on display in the U.S. Capitol; the Senate commissioned it in 2002.

Edward Brooke

Edward Brooke (Daily News Archive via Getty Images)

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The first African American elected to the Senate by popular vote, Brooke, a Republican from Massachusetts, is a Howard University and Boston University Law School graduate who was also in the Army during World War II. He served two full terms in the Senate, from 1967 to 1979. Brooke was busy while he was there, pushing tirelessly for low-income housing, an increase in the minimum wage and racial equality in the South.

Carol Moseley Braun

Carol Moseley Braun (Chris Sweda-Pool/Getty Images)

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Braun, of Illinois, was one of five female senators elected in 1992, which was dubbed "the Year of the Woman." As the first African-American woman in the role, she pushed progressive education bills and campaigned for gun control. In 2004 she set her sights even higher and ran for the Democratic nomination for president.

Barack Obama

President Barack Obama (Saul Loeb-Pool/Getty Images)

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It was while he was serving as an Illinois state senator that now-President Obama made the speech at the 2004 Democratic National Convention that got him noticed and launched his journey to becoming a U.S. senator. You know the rest of the story: It wasn't long before he was the 44th (and first African-American) president of the United States. 

Roland W. Burris

Roland W. Burris (Scott Olson/Getty Images)

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Burris was elected comptroller of Illinois in 1978, becoming the first African American to win a statewide election in Illinois. After more than 10 years in that role, the Democrat became attorney general of Illinois and ultimately filled Barack Obama's vacancy in the Senate. He was appointed on Dec. 31, 2008.

Tim Scott

Tim Scott (Bill Clark/CQ Roll Call/Getty Images)

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Appointed to the Senate on Jan. 2, 2013, Scott became the first African American since Reconstruction to represent a Southern state in the Senate. The Republican brought a background in insurance and real estate, a stint on the Charleston County, S.C., council and a year's experience in the South Carolina House of Representatives. Scott served a term in the U.S. House of Representatives before his appointment to the Senate.

William "Mo" Cowan

William "Mo" Cowan (Sarah L. Voisin/Getty Images)

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When Cowan, a Democrat, was appointed Massachusetts senator on Feb. 1, 2013, he helped set a record: It was the first time that two African Americans (he and Tim Scott) served simultaneously in the U.S. Senate. Cowan made his way to the Hill after a career as chief legal counsel and chief of staff to Massachusetts Gov. Deval Patrick.

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