Mass incarceration has become the elephant in the room of modern American history, a panel of historians said Tuesday at Yale University.

It has implications for the way we examine politics, education, labor, the economy and race, according to the panel. Yet historians have barely started to analyze and interpret the effect of prisons on the national narrative.

“This is the story. This is the fundamental story,” said Heather Ann Thompson, an associate professor of history at Temple University. “There is no area this does not touch.”

The discussion, “Incarceration in America, Past and Present,” featured Thompson; Khalil Gibran Muhammad, director of the New York Public Library’s Schomburg Center for Research in Black Culture; and Caleb Smith, a Yale University English professor who is editing an edition of the earliest known African-American prison narrative. David Blight, director of Yale’s Gilder Lehrman Center, moderated the panel.

Blight started by noting that in New Haven alone, roughly 1,200 prison inmates return to the city from prison every year. More than 2 million Americans are in jail.

Examining the history of prisons is “deeply and disturbingly contemporary, to say the least,” Blight said.

Smith said the U.S. prison system gradually has shed its idealistic underpinnings as a system of justice and rehabilitation. Instead, prisons are seen as a source of security, to be managed as efficiently as possible.