Massachusetts Rep. Jim McGovern was there Wednesday when the newly freed Alan Gross arrived at Andrews Air Force Base in Maryland.
"John Kerry's plane flew in around the same time and Alan said to the secretary of state, 'Thank you for not forgetting me,'" McGovern said.
McGovern, who has long been pushing for changes to America's policy toward Cuba, told BuzzFeed News that he and other members Congress who were part of the delegation only found about the Gross' release from a Cuban jail last night.
Vice President Joe Biden called McGovern on Tuesday night to share the news. McGovern called Gross "gracious and grateful" to lawmakers.
The release of Gross came as a part of a broader agreement between the two countries to try and "normalize" relations. Three Cuban spies were also released as part of the deal. The move was blasted by members of Congress deeply critical of Cuba's government such as Sen. Marco Rubio and Democratic Sen. Bob Menendez.
McGovern said he was completely surprised by the announcement.
"The most I ever got from the administration was 'We're sympathetic, we're in agreement with you, we're working on it, we're working on it, trust us we're working on it,'" he said. "That's all I've heard for years, so I don't know when this deal was sealed until the heads-up I was given last night."
McGovern said that the imprisonment of spies in the United States and Gross' imprisonment had been a "roadblock" to improving relations between the countries.
"I think the issue of Alan and the three Cuban prisoners in the United States basically were roadblocks for anything good to happen between the U.S. and Cuba," he said. "Because of this humanitarian gesture by the United States government, paved the way for the president to think big and bold.
"There are human rights problems in Cuba and no one denies and no one should be silent about that and I've met with dissidents in Cuba who have been jailed who say please change your policy because your policy enables this government to be repressive," he added.