When a nation mourned. Or did it?

Few events in American history unleashed deeper and more profound mass mourning than the assassination of Abraham Lincoln 150 years ago, on April 15, 1865. In the north, Lincoln was the recently (and overwhelmingly) re-elected president, a revered orator-oracle and the victorious commander in chief in the Civil War, which, however brutal and costly, had just secured the future of the nation and achieved the destruction of slavery.

Only six weeks earlier, at his second inauguration, Lincoln had brought tears to the eyes of many among the 40,000 spectators when he pleaded for 'malice toward none' and 'charity for all,' urging his fellow citizens to help him 'bind up the nation's wounds.'

On April 4, he had entered the conquered Confederate capital of Richmond, Va., to a tumultuous reception from the city's African-Americans — a welcome so joyously uninhibited that the president felt compelled to beg one man to 'kneel only to God and thank Him for the freedom you are about to enjoy.' On April 9, Robert E. Lee surrendered his Army of Northern Virginia to Ulysses S. Grant at Appomattox Court House, Va., effectively ending the war, and church bells throughout the north pealed in celebration.

When the tolling resumed — this time in acknowledgment of the slain president, it was coincident with milestones of the religious calendar. Shot on Good Friday, Lincoln was mourned in churches across the north on Easter Sunday as a Christ-like savior who died for his nation's sins and who would rise into American mythology. During Passover-week Sabbath services a day earlier, he was compared to the Hebrew liberator Moses, who had freed his people and led them to the Promised Land — only to die before he could see it himself.

All that said, lamentation for Lincoln was far from universal, even in the north. Some Northern soldiers — 'Lincoln's Men,' as author William C. Davis has called them — particularly Democrats, seemed more eager to celebrate than mourn. James Walker of the 8th California Infantry, for one, blurted out his opinion that the late president was 'a Yankee son of a b---h' who 'ought to have been killed long ago.' For this outburst he was court-martialed and sentenced to death, but an appeals court commuted the harsh sentence. In the Confederacy, the Chattanooga Daily Rebel lived up to its insurrectionary name by crowing: 'Old Abe has gone to answer before the bar of God for the innocent blood which he has permitted to be shed, and his efforts to enslave a free people' — meaning Southern whites.

Nor were Southern racists and fiercely anti-Lincoln Northern Democrats the only ones who welcomed the president's death. As historian Martha Hodes reminds us in her new book, 'Mourning Lincoln,' Radical Republicans, the most liberal members of the president's party, had feared for years that Lincoln would make Reconstruction too easy for the Confederate States and their leaders and make the achievement of civil rights too hard for newly freed African-Americans.

Rep. George Julian of Indiana, who had criticized Lincoln for his so-called 'policy of mercy,' confided to his diary after the assassination that the 'universal feeling among radical men here is that his death is a godsend.' Sen. Zachariah Chandler of Michigan agreed. God had permitted Lincoln to live, he told his wife, only 'as long as he was usefull & then substituted a better man to finish the work.'

By 'a better man' Chandler meant Andrew Johnson, the vice president who succeeded Lincoln. In this assessment, as it turned out, Chandler and other progressives proved dead wrong. Though Johnson (unlike Lincoln) harbored a 'usefull' hatred for the Southern aristocracy, he possessed no benevolence at all for African-Americans. Johnson proved deeply racist — a horrendous choice for second spot on the 1864 Republican ticket — and by 1865 was intractably opposed to civil and voting rights for ex-slaves. For the next four years, Congress would wage a fierce struggle with Johnson over Reconstruction policies, a battle that led to his impeachment. He survived his Senate trial by a single vote.

Unknown until then was the spark that set off the man who arguably hated Lincoln most of all. At Johnson's impeachment trial it was revealed that Lincoln's assassin, John Wilkes Booth, had been inspired to slay the president after hearing him speak publicly on Reconstruction from the White House on April 11. That night, Lincoln did just what his progressive critics doubted he would do: He became the first American president to propose suffrage for 'the colored man,' albeit at first only for 'the very intelligent and … those who serve our cause as soldiers.'

Not enough to satisfy the Radical Republicans, perhaps, but more than enough to send the already frustrated and unhinged Booth into a frenzy of revenge. 'That is the last speech he will ever make,' Booth vowed to a cohort in the crowd that evening.

It was.

And for many — though admittedly not all — Americans, the mourning continues.

Harold Holzer is the author, most recently, of 'President Lincoln Assassinated!!' and 'Lincoln and the Power of the Press.' From the Los Angeles Times.