With ''The Conspirator," film director Robert Redford and The American Film Company have brought to the movie screen an honest portrayal of the final tragedy of the American Civil War which occurred from May to July of 1865 at what we today know as Fort Lesley J. McNair.

On April 15, 1865 the actor John Wilkes Booth assassinated President Abraham Lincoln at Ford's Theater. At the same time Booth sent George Atzerodt to assassinate Vice President Johnson and Lewis Powell (also known as Paine) to assassinate Secretary of State William H. Seward. Atzerodt, however, got cold feet, became drunk and went home. Powell attempted to murder Seward with a pistol and a large Bowie knife and did seriously wound him. Later he would show up at Mary Surratt's boarding house on H Street in what is today known as Chinatown.

The U. S. government, under the direction of Secretary of War Edwin Stanton (portrayed by actor Kevin Kline), immediately set about to round up the conspirators, try them under military law, and execute them at the Washington Penitentiary.

Presently under the U.S. Constitution it is illegal to try civilians in a military court in an area where civilian courts are functioning. As a lawyer Stanton knew this and still ordered that the alleged conspirators be so tried. And then he did things that you won't see in the movie but are hinted at.

Prosecution witness Henry Von Steinacker turns out to have been a Union Soldier who escaped before being punished for desertion. He then joined the Confederate army where he was convicted of stealing and of abusing Union prisoners of war. When the defense counsel challenged his testimony, Maj. Gen. Lew Wallace, sitting as a member of the military tribunal, declared that he held the defense attorney in ''supreme contempt."

Next came James Merritt, who gave perjured testimony against the defendants. The truth came out after their execution when newspaper reporters found out that Merritt had been given $6,000 by the U. S. government to give the perjured testimony.

Yet another prosecution witness, one Sanford Conover, was later convicted of giving perjured testimony and sentenced to ten years in a federal penitentiary.

Louis Weichman, who is portrayed in the movie as giving questionable testimony against Surratt, was a weak-willed alcoholic who was personally threatened by the secretary of war to testify against Surratt. Whatever he said could not be believed.

Now we come to Surratt. Married at age 16 to an alcoholic older man, she had a life of hardship in which her only happiness was her children.

Her husband had died leaving her deeply in debt so she had to work two jobs, one as a boarding house owner in downtown D.C., and the other as postmistress of the U.S. Post Office at present day Clinton, Md.

Yes, she had been involved in the 1864 kidnapping plot against Lincoln that had failed due to the president's last minute change of plans in going from the White House to Anderson Cottage (located at the current Armed Forces Retirement Home in D.C.). But a kidnapping plot that hadn't been carried out isn't grounds for execution by hanging.

What was eating away at the secretary of war was his inability to capture Surratt's son John, who was a Confederate intelligence agentAcA "courier and best friend of John Wilkes Booth.

As you will see in the movie John Surratt escaped from Maryland to Canada and then Rome before finally landing in Alexandria, Egypt, where he was arrested and returned to the U.S. in 1867 to stand trial.

But John Surratt was twice tried in a civilian court of law in Maryland with his full constitutional rights. In both of his trials he was acquitted due to a hung jury.

What would have been Mary Surratt's fate had she been given a civilian trial with her constitutional rights'