The Amistad was a Spanish slave ship transporting slaves from Cuba to an unknown destination, presumably an illegal destination in the southern United States. The slave trade had been outlawed by the United States in 1808 and by Great Britain a year earlier, but Southern plantation owners continued to buy slaves in defiance of the law, particularly from Spanish slave traders. Before the Africans could be off-loaded, however, they managed to overpower the ship's crew and demanded to return to their homeland on the west coast of Africa. The Africans lacked navigational skills, however, so they were tricked by the two surviving white crewmen who steered the Amistad north along the American seaboard until it was captured by an American navy ship. Connecticut authorities charged the Africans with the murders of their former captors. But the abolitionists who undertook their defense argued that because the slave trade was illegal, their actions could only be understood as self-defense.

With a script by David Franzoni, Spielberg's Amistad tells this story from the moment the African leader Cinque (Djimon Hounsou) frees himself in the bowels of the slave ship until Adams' magnificent oratory before the Supreme Court. Along the way, we meet Yamba (Razaaq Adoti), a rival leader among the Africans; Theodore Joadson (Morgan Freeman), a former slave who is now a leading abolitionist; Lewis Tappan (Stellan Skarsgard), a leading white abolitionist; and Roger Baldwin (Matthew McConaughey), the young real estate lawyer who handles the Africans' case until he turns it over to Adams.

Amistad is a superb history lesson. Few will soon forget the horrors of the infamous Middle Passage, where slaves are purchased from a holding prison on the African coast and then packed like sardines onto rough wood platforms in the ship hold. Once there, they are forced to lie in their own excrement, half-starved and fed only occasional handfuls of disgusting mush. When provisions run low, more than four dozen people are weighted with stones and thrown into the sea to drown. For some, the prospect of a life in slavery is so depressing they opt for suicide.

In another historical regard, Amistad nicely illustrates the way politics so often embraces strategies over people. With callous disregard for the human lives at stake, President Martin Van Buren (Nigel Hawthorne) tries to employ the Amistad case as a mechanism for appeasing the pro-slavery elements in his own Democratic Party. He injects the federal government into the proceedings, arguing that the Amistad Africans should be returned as property of the queen of Spain. Elsewhere, Spielberg effectively flays the ancient sophistry that Africans themselves practiced slavery and, in fact, were collaborators in the slave trade. Yes, and so what? The fact that black men enslave black men on one continent hardly justifies black men being enslaved by white men on another.

Meaningful and otherwise effective as this film often is, it still falls a good ways short of true greatness. Spielberg made a mistake when he decided to open his tale with the rebellion aboard the Amistad. The action isn't rendered very clearly. And we haven't any clear idea of what's at stake or even who is who. Had the film started with Cinque's capture just outside his African village and followed through his journey on the Middle Passage (episodes now rendered in flashback), the revolt would have packed a much greater emotional wallop. The film is by no means too long, but Spielberg could still have dispensed with those passages showing the 11-year-old Spanish Queen Isabella (Anna Paquin) petulantly demanding her slaves back. Van Buren doesn't care a fig about Isabella; he cares about Southern Democrats. Still, the picture fails to show us why the South cares so much about the fate of the Amistad survivors. John C. Calhoun (Arliss Howard) drops by the White House to campaign against the Africans but never makes clear why this case matters so much when some men of color live as "freedmen" in the South and are free throughout the North.

Some of the film's developments are astonishingly clumsy. Joadson's effort to recruit Adams, for instance, is painfully false. His entire speech about Adams' family history is aimed not at the character but at the uninformed viewer. Equally awkward is a passage detailing Yamba's fascination with Christianity based on pictures in a Bible he can't read. Why would someone want to convert to the religion of a people holding him in chains? Yamba isn't even the beneficiary of any proselytizing acts of kindness. And the sour, one-note character of Tappan seems introduced purely to show how political zealots can lose sight of the trees out of concern for the forest.

Even the plotting in the movie falters. We don't know how Van Buren manages to replace the Amistad judge right in the middle of the original trial. And under rules of double jeopardy (if indeed they apply -- which we also don't know), we don't understand how the government can appeal its case to the Supreme Court. Just before the final decision, we are told that seven out of the nine Supreme Court justices are Southern slaveholders. So if the case is as central to the South as Calhoun insists, how does Adams convince them? It won't be long afterwards, remember, that the Supreme Court will rule in the Dred Scott case that Congress has no constitutional power to prohibit slavery in the territories, a decision that practically guarantees civil war.

In the end, it would appear that Spielberg lacked full faith in his own story. This powerful material is undermined rather than enhanced by the pushy choral score the director employs to hype his climactic passages. Then, Spielberg closes with a sequence showing the destruction of an African slave fortress, an event only tangentially related to the Amistad. Presumably, the director feared the Supreme Court triumph would not provide enough emotional payoff. It doesn't quite, oddly enough. But surely it could have.