President Joseph E. Aoun, more than 400 Northeastern alumni and co-op students, and members of the Massachusetts Congressional delegation gathered on Capitol Hill on Wednesday night to honor alumnus Mo Cowan, who since February has served as interim Massachusetts Senator, filling the seat vacated by John Kerry when he became Secretary of State.

Aoun and Jeremy Paul, dean of the School of Law, hosted the Capitol Hill reception in the Russell Senate Office Building’s Kennedy Caucus Room. Aoun said Cowan had been a strong supporter of Northeastern while working as chief of staff for Massachusetts Gov. Deval Patrick and now in the U.S. Senate, and he commended the Northeastern alumnus for his bipartisan approach in Washington.

“Both sides of the aisle love this guy,” Aoun said. “We attribute that to the fact that he has a Northeastern education.”

Cowan earned his law degree from Northeastern in 1994, then went on to a career in public service, most recently serving Gov. Deval Patrick in a number of capacities, including chief legal counsel, chief of staff, and senior counselor. He will stay in the Senate until a special election, to be held June 25, decides a permanent successor to Kerry.

“It’s an honor to be in the Senate, it’s an honor to represent the people of Massachusetts, and it’s equally an honor to represent that fine institution on Huntington Avenue and be the first Husky in the Congress,” Cowan said.

Members of the Massachusetts Congressional delegation in attendance included Sen. Elizabeth Warren, Rep. James McGovern, Rep. Joseph Kennedy III, and Rep. Niki Tsongas. Sen. Debbie Stabenow of Michigan, chair of the Senate Agriculture committee of which Cowan is a member, also attended.

Aoun’s visit to Washington also brought him to the State Department, where he met with officials to discuss global co-op and opportunities for the federal government and Northeastern to collaborate on future educational and cultural exchange initiatives. He also discussed Northeastern’s Global Health Initiative, which last week brought together faculty members Michael Pollastri, Graham Jones, and Kim Lewis and State Department staff members to discuss applying drug discovery expertise to neglected diseases like malaria, tuberculosis, and sleeping sickness.

After the Cowan reception, Aoun attended a nearby fundraiser for the One Fund Boston, held on the one-month anniversary of the Boston Marathon bombings, an event that organizers say every member of the Massachusetts Congressional delegation would attend. On Thursday, Aoun will attend a State Department luncheon honoring Turkish Prime Minister Recep Tayyip Erdoğan hosted by Kerry and Vice President Joe Biden.