The names of three men who once dominated the Senate’s halls of power are lettered in gold onto each limestone front of the stately Senate office buildings just across from the Capitol — honorifics reserved for an elite few.

There is the building named after Philip Hart, the Democrat from Michigan who was known as “the conscience of the Senate.” Connected to it is a second building named after Everett Dirksen, Republican of Illinois and a key player in the passage of the Civil Rights Act of 1964.

Standing alone is the Russell building, a telling divide for the structure’s namesake, Richard B. Russell Jr.

While Mr. Dirksen famously broke the Southern filibuster of the Civil Rights Act, allowing the landmark anti-discrimination legislation to pass, Senator Russell of Georgia, a towering New Deal Democrat whose Senate career spanned four decades, led the filibuster that almost killed the bill, a show of defiance that underscored his strident support of racial segregation and white supremacy.