U.S. Attorney General Jeff Sessions, a son of the old South, praised Abraham Lincoln on Monday in Philadelphia as a leader with "moral and legal clarity" whose actions paved the way for the emancipation of slaves.

Appearing before 825 people at a sold-out luncheon at the Union League of Philadelphia to receive its Lincoln Award, Sessions joked that the league, founded in 1862 to support the Union and the policies of the 16th president, had never given its most prestigious award to someone with such an archetypally Southern name as Jefferson Beauregard Sessions III.

Sessions, a former Alabama senator whose tenure as the nation's top law-enforcement official has been rocked by public rebukes from President Trump, noted with pride that other recipients of the award have included former Pennsylvania Gov. and U.S. Attorney General Dick Thornburgh, and Supreme Court Justices Clarence Thomas and Samuel A. Alito Jr.

Earlier in the day, Sessions raised eyebrows and was accused of racism by some for telling attendees at the National Sheriffs Association winter meeting in Washington that "the office of sheriff is a critical part of the Anglo-American heritage of law enforcement."

Ian Prior, a Department of Justice spokesman, defended Sessions' use of "Anglo-American" as a common legal term. "As most law students learn in the first week of their first year, Anglo-American law — also known as the common law — is a shared legal heritage between England and America. The sheriff is unique to that shared legal heritage. Before reporters sloppily imply nefarious meaning behind the term, we would suggest that they read any number of the Supreme Court opinions that use the term. Or they could simply put 'Anglo-American law' into Google," Prior said.

In his Philadelphia speech, Sessions went out of his way to not just praise Lincoln, but to make clear that Southerners were on the wrong side of history. "Though many Southerners try to say otherwise — and I love the Southern people —  slavery was the cause of the war. It was not states' rights or tariffs or agrarian vs. industrial economies," Sessions said.

"And the failure, the refusal of the South, to come to grips with it — really to actually change this immoral system of enslavement — led to the explosion," he added.

Sessions said the Justice Department under his direction honors Lincoln daily by upholding the rule of law and the Constitution.

Examples he cited included cracking down on violent street gangs such as MS-13 and "sanctuary city" laws, and challenging 19 injunctions handed down by federal judges around the country stopping the administration from implementing its policies.

"Unfortunately, time and again, those who could not achieve their policy goals at the ballot box have attempted to impose them on their fellow citizens by other means," Sessions said of judges.

"We have seen this in decisions by unelected judges who redefine the meaning of words to establish policies that Congress never intended. Policies the people never approved," said Sessions, drawing thunderous applause when he said the administration would win most of the legal challenges.

Sessions said cities such as Philadelphia  that have enacted sanctuary city laws are in effect seeking to nullify federal immigration laws, and are losing federal funding as a result.

"We have seen jurisdictions attempt to nullify federal immigration law under so-called sanctuary policies. One hears activists and a few officials even talk of nullification and secession. Let them come here to the Union League — or Gettysburg — if they'd like a legal and historical lesson on those subjects," Sessions said.