The impeachment inquiry and trial of President Donald Trump is set to end Wednesday with his acquittal in the Republican-held Senate, but not without the monthslong process pulling dozens of private attorneys into the fray.

Lawyers from Big Law found themselves sitting in the House basement's secure facilities as their clients served as witnesses in the impeachment inquiry, and some repeated the performance during the public hearings with the House Intelligence Committee.

Others were hired to work behind the scenes with lawmakers building the case for impeachment, offering constitutional and legal expertise. Some of those attorneys found themselves in a starring role during the House hearings, questioning witnesses.

Those witnesses, most of whom were civil servants, ended up footing legal bills for lawyers with the specific knowledge needed to guide them through the rare proceedings.

A number of congressional and administration lawyers also worked on the impeachment inquiry. Former federal prosecutor Daniel Goldman, now the chief investigator for the House Intelligence Committee, played a starring role in questioning witnesses at hearings. GOP lawyer Stephen Castor, a longtime staffer on Capitol Hill, was Goldman's counterpart for Republicans during both the closed-door depositions and public hearings.

The House Judiciary Committee had hired former Obama White House ethics lawyer Norm Eisen and Kramer Levin Naftalis & Frankel partner Barry Berke—who's on leave from the firm—last year, as the panel prepared to go to court to seek information that could help make the case for impeachment. Both attorneys have also questioned witnesses during public hearings.

Here's a rundown of the lawyers who took part in the historic impeachment proceedings against Trump.

Robert Luskin of Paul Hastings, a lawyer for Gordon Sondland. (Photo: Diego M. Radzinschi / ALM)

Witnesses

Robert Luskin, Kwame Manley & Daniel Holman: The Paul Hastings team represented the ambassador to the European Union, Gordon Sondland, who testified there was in fact a quid pro quo over the Ukrainian military aid in exchange for a White House meeting.

Andrew Bakaj & Mark Zaid: Bakaj, who runs his own firm, Compass Rose, was initially hired by the whistleblower whose complaint started the inquiry. Zaid was then added to the legal defense team. Both men have experience representing whistleblowers, and Bakaj himself was a government whistleblower who faced retaliation for filing a complaint while working at the CIA.

James McDermott: McDermott, of the Portland, Oregon-based firm Ball Janik, was also on Sondland's legal team. Sondland founded a Portland hotel company which owns several properties in the city.

Lawrence Robbins, Laurie Rubenstein & Rachel Li Wa Suen: The team from Robbins, Russell, Englert, Orseck, Untereiner & Sauber represented former U.S. Ambassador to the Ukraine Marie Yovanovitch during the inquiry. Robbins and others at his firm are also working on the House's Supreme Court case seeking Trump's tax records from the accounting firm Mazars.

Margaret Daum: The Squire Patton Boggs partner pulled double duty in the impeachment inquiry, representing both acting assistant secretary of state for European affairs Philip Reeker and former special envoy to Ukraine Kurt Volker.

John Cella: Cella of Arnold & Porter Kaye Scholer represented Secretary of State Michael Pompeo's adviser Michael McKinley in his closed-door deposition.

John Bellinger: Bellinger, also of Arnold & Porter, joined Cella in representing McKinley. He was also the attorney for then-acting ambassador to Ukraine Bill Taylor.

Jeffrey Smith: Smith, the former head of Arnold & Porter's national security practice and ex-general counsel of the CIA, also joined Bellinger in representing Taylor in the impeachment inquiry.

Samuel Ungar & Lee Wolosky: Ungar and Wolosky of Boies Schiller Flexner represented former National Security Council official Fiona Hill. Wolosky recently left the firm to join Jenner & Block.

Michael Volkov & Matthew Stankiewicz: Lt. Col. Alexander Vindman, a Ukraine expert on the National Security Council who was on Trump's July 25 call with Ukrainian President Volodymyr Zelensky, hired the attorneys from The Volkov Law Group for his testimony. Voklov previously worked as an assistant U.S. attorney at the U.S. Attorney's Office for the District of Columbia.

Whit Ellerman: Robert Blair, a top aide to White House chief of staff Mick Mulvaney, hired Ellerman of the boutique firm Ellerman Enzinna as he refused to cooperate with the House's impeachment inquiry. Ellerman, a former federal prosecutor, told media outlets that Blair was complying with the White House's direction to not testify in the proceedings.

Charles Cooper: Cooper, of the firm Cooper & Kirk, is a legal heavyweight for Republicans on Capitol Hill, previously representing former Attorney General Jeff Sessions. He spearheaded the lawsuit from former deputy national security adviser Charles Kupperman over the House subpoena for his testimony in the impeachment probe, and is also representing former national security adviser John Bolton.

Jeffrey Dannenberg: Another associate of Rudy Giuliani, Seymon "Sam" Kislin, hired New York attorney Dannenberg of Kestenbaum, Dannenberg & Klein to handle House subpoenas for information. Dannenberg told media outlets that Kislin was cooperating with the committees after reaching an "understanding" with lawmakers.

John M. Dowd (Photo: John Disney/ALM)

John Dowd: The former White House lawyer apparently got the sign-off from Trump to represent Giuliani associates Igor Fruman and Lev Parnas as they were indicted for campaign finance violations. Parnas has since dropped him as a lawyer.

Joseph Bondy: Now representing Parnas is Bondy, a cannabis lawyer who is accompanying Parnas on his media blitz alleging close ties to Trump and the actions he took in connection with the push to get Ukraine to launch investigations into the Bidens.

William Pittard: Acting chief of staff Mick Mulvaney hired the KaiserDillon partner as he considered filing his own lawsuit in November over a House subpoena issued in the impeachment inquiry. However, Pittard indicated in a later court filing that Mulvaney would not sue and instead "rely on the direction of the president" in not appearing for his requested deposition.

Robert Driscoll, Daniel Plunkett & Alfred Carry: Mulvaney then turned to Driscoll, the head of McGlinchey Stafford's Washington, D.C. office, to defy the congressional subpoena and more recently deny allegations reportedly made about Mulvaney in Bolton's unpublished manuscript. Plunkett and Carry are also on Mulvaney's team at McGlinchey Stafford.

William Burck: The Quinn Emanuel Urquhart & Sullivan partner is a familiar presence for Republicans seeking legal advice, representing figures like Stephen Bannon. Both Secretary of State Mike Pompeo and National Security Council lawyer John Eisenberg hired Burck for the impeachment inquiry.

Paul Butler: National Security Council lawyer Michael Ellis tapped Butler, a partner with Akin Gump Strauss Hauer & Feld, as Ellis defied a House subpoena for his testimony in the impeachment inquiry.

Justin Shur, Emily Damrau, Elizabeth Sawyer & Caleb Hayes-Deats: Jennifer Williams, an adviser to Vice President Mike Pence, brought on board the team from MoloLamken as she became one of the few current administration officials to comply with a House subpoena for her testimony.

Andrew Wright, Barry Hartman & Nancy Iheancho: Deputy Assistant Secretary of State George Kent hired the K&L Gates lawyers as he testified both publicly and privately in the House impeachment proceedings.

Jon Sale: Sale was the first lawyer hired by Rudy Giuliani as part of the impeachment inquiry. Sale, a former Watergate prosecutor currently with Nelson Mullins Riley & Scarborough, wrote the letter to House investigators saying that Giuliani would not comply with a subpoena for documents. That was the extent of his representation of the president's personal lawyer.

Eric Creizma & Melissa Madrigal: Giuliani later announced that he had hired Creizman and Madrigal of Pierce Bainbridge Beck Price & Hecht as the House moved forward with its impeachment inquiry.

Robert Costello: Giuliani also tapped Costello, a lawyer at Davidoff Hutcher & Citron who briefly represented Trump's ex-personal lawyer Michael Cohen, to represent him in the impeachment proceedings. Costello and Giuliani have known each other for nearly 50 years.

Daniel Levin: Laura Cooper, a deputy assistant secretary of defense, hired Levin of White & Case for her testimony with House investigators on what she knew about the hold on Ukrainian military aid.

Mark MacDougall & Abbey McNaughton: Catherine Croft and Christopher Anderson, both Ukrainian specialists with the State Department, each hired MacDougall and McNaughton of Akin Gump for separate closed-door depositions in the inquiry.

Barbara "Biz" Van Gelder, Allegra Kauffman & Karen Williams: The team of attorneys with Cozen O'Connor represented senior career Office of Management and Budget official Mark Sandy in his closed-door deposition with congressional investigators. Van Gelder also represented former National Security Council official Tim Morrison.

Hannah Cornett: The Cozen O'Connor associate joined Van Gelder in representing Morrison during his testimony.

Ken Wainstein, Paul Nathanson & Katherine Swan: David Holmes, a career diplomat who overheard a call between Sondland and Trump while working at the U.S. Embassy in Ukraine, hired the Davis Polk & Wardwell team to guide him through his testimony.

Brian Glasser & Cary Joshi: David Hale, the under secretary for political affairs at the State Department, was represented by Glasser and Joshi of Bailey Glasser for his questioning by House investigators.

House

Joshua Matz: Matz, who co-authored a book on impeachment with Harvard's Laurence Tribe, went on leave from his firm Kaplan Hecker & Fink to help the House Judiciary Committee with its role in the impeachment inquiry.

David O'Neil, Anna Moody and Laura O'Neill: House managers listed the Debevoise & Plimpton attorneys as helping to draft their briefs filed in the Senate impeachment trial. The firm is also working on the House lawsuit seeking documents on the Trump administration's failed effort to add a question on citizenship to this year's census.