With Rep. Elijah Cummings' death, Capitol Hill loses a widely respected lawmaker who brought gravitas to his role as a key player in challenging President Donald Trump. The longtime Democratic representative and chairman of the House Committee on Oversight and Reform died Thursday at age 68 due to what his office called longstanding health challenges. The lawmaker, who represented major parts of Baltimore and its outskirts since 1996, was seen as an advocate for cutting prescription drug prices, fighting addiction, strengthening gun control and reforming the criminal justice system. Cummings gained more national prominence in recent years, especially in the aftermath of the widely covered death of Freddie Gray, a 25-year-old black man, in Baltimore Police Department custody. His role as chair of the House Oversight Committee put him in the position of being a major foil to Trump, and in a leading spot in the chamber's impeachment inquiry into the president. Here are some of the major moments from Cummings' career.

Early successes

Rep. Elijah Cummings, D-Md. Winner of Democratic Primary of Maryland's 7th Congressional District with a supporter, after forum held at Bibleway Missionary Baptist Church on Feb. 27, 1996. Maureen Keating | CQ-Roll Call, Inc. | Getty Images

After working as a lawyer in Baltimore, Cummings won a seat in the Maryland General Assembly. He served in that position from 1983 to 1996, becoming the first African American to be named speaker pro tempore in Maryland. He then ran for Maryland's 7th Congressional District in a 1996 special election. He won the congressional seat and had held it since. Cummings led the Congressional Black Caucus in 2003 and 2004.

Freddie Gray's death

Rep. Elijah Cummings pleads with protestors to go home rather than risk arrest in Baltimore, as protestors walk for Freddie Gray, April 29, 2015. Samuel Corum | Anadolu Agency | Getty Images

Cummings' national fame grew in the wake of Gray's death, which came amid a national reckoning over police use of force against unarmed black men. He gave an impassioned speech at Gray's funeral in April 2015, promising "we will not rest until we address this and see that justice is done." Referencing the news cameras present at the funeral, he asked, "Did anyone recognize Freddie when he was alive?" Cummings gained further recognition during the early May 2015 riots that followed charges against six police officers who took Gray into custody. Standing between a crowd and police with a bullhorn, he urged protesters to go home ahead of a city curfew. "We came here because we love you," he said, according to The Washington Post. None of the officers was convicted on charges related to Gray's death.

The Trump era

House Oversight and Government Reform Committee ranking member Rep. Elijah Cummings (D-MD) speaks during a news conference with House Intelligence Committee ranking member Rep. Adam Schiff (D-CA) (L) and House Democratic Caucus chairman Rep. Joe Crowley (D-NY) at the U.S. Capitol May 17, 2017 in Washington, DC. Getty Images