The United States Congress has a rich history with significant contributions from Black Americans. Some notable milestones include:

1. Hiram Rhodes Revels - In 1870, Hiram Rhodes Revels became the first Black member of Congress when he was elected to the U.S. Senate from Mississippi. He served a one-year term during the Reconstruction era.

2. Shirley Chisholm - In 1968, Shirley Chisholm became the first Black woman elected to Congress, representing New York's 12th Congressional District. She went on to make history again in 1972 as the first Black woman to run for the Democratic Party's presidential nomination.

3. John Lewis - John Lewis was a prominent civil rights activist who later served in Congress representing Georgia's 5th Congressional District. He was a key figure in the Civil Rights Movement and continued to champion civil rights causes during his time in office.

4. Barbara Jordan - Barbara Jordan made history in 1972 when she was elected as the first Black woman from the South to serve in Congress. She represented Texas in the U.S. House of Representatives and was known for her powerful speeches and advocacy for social justice.

5. Kamala Harris - Kamala Harris made history in 2017 when she was sworn in as the first Black and South Asian woman to represent California in the U.S. Senate. She later became the first Black woman to be elected Vice President of the United States in 2020.

These are just a few examples of the trailblazing Black Americans who have served in the U.S. Congress and made lasting impacts on American history and politics.