Martin Scorsese says he’s wanted to create Gangs of New York for 30 years. That was when he first read Herbert Asbury’s 1928 historical saga of the same name. The film is loosely based on that book, and the story that emerges is an engrossing and terrible tale of war, hatred, lust and revenge. The epic begins in 1846 with a street war between Irish-Catholic immigrants and Protestant New York "nativists." The immigrants, led by a man known as Priest Vallon, fight to carve out a piece of the new world for themselves and for those who follow. William "The Butcher" Cutting and his warriors aim to fend off what they see as the invading hordes. Both fight in the name of God. Both fight for dignity and life.

That initial battle is won by The Butcher. As Cutting’s knife takes Vallon’s life, and scatters the immigrant mob, Vallon’s young son (who later becomes known as Amsterdam) watches every wound, soaking in the malevolence that causes them. Sixteen years later, after growing up in an orphanage far from sight and out of mind, he arrives back at the Five Points, bent on revenge. Known for its sweltering night life, fast-fingered pickpockets and lawless violence, the Five Points serves as Cutting’s headquarters. To get close to The Butcher, Amsterdam joins his gang and works his way up to the status of second-in-command. Then, on the anniversary of his father’s death, he stages his attack.

While Civil War rages in the South, and life and death swirls through the Five Points, love and lust grimly fight for dominance under cover of night. Amsterdam meets Jenny, a skilled pickpocket and "turtledove" (a woman who dresses up as a maid to steal from the rich), and the two kindred spirits immediately begin smooching and sparring. It’s his best friend, Johnny, who is responsible for introducing him to Cutting and his gang, but turbulence lies ahead for the two men as well. Ultimately, Amsterdam’s private grudge match with Cutting is transcended by the 1863 Civil War Draft Riots. And what has seemed like such a monumental issue throughout the story is submerged in a hail of cannon fire. Laced with as much character development as a Jeff Shaara novel, Gangs bludgeons sensibility while delicately tapping a wide range of subconscious fears. The themes are astonishingly human, the history spectacular and more than little frightening.

• spiritual content: Faith in God (or at least lip service to such a faith) fuels war as Protestants and Catholics clash in the New World just as they had in the Old. The Priest and his men take communion before facing off with The Butcher. Everyone prays that God will bless their endeavors and scour their enemies from the face of the earth. Vallon teaches his son to pray to St. Michael, who "cast Satan out of Paradise." Taunting the immigrants before a battle, Cutting yells, "Let the Christian Lord guide my hand!" Vallon retorts, "Prepare to receive the true Lord!" Years later, after being exhorted by a priest to forgive those who wronged him, Amsterdam tosses his Bible into the river and sets off to seek their death. After picking a person’s pocket, Jenny is fond of smirking, "I leave you in the grace and favor of the Lord." When a preacher urges Amsterdam to come to church, Amsterdam responds, "Go to h---." One man credits Shakespeare for writing the King James Bible. The Holy Spirit is said to give men the courage to kill ("I’ve got the steam of the Holy Spirit in my spine"). To indict a politician for straddling the fence on immigration issues, Cutting quotes Revelation 3:16.

• nudity and sexual content: Dances and drunken parties turn into orgies of exhibitionism and public sex. Classic statues of nude women are displayed, but those stone ladies aren’t the only ones who are naked. Bare-breasted women (many of them prostitutes) are seen dancing, being groped and having sex. Completely nude, two women cuddle together on a bed while Cutting watches. In another scene, two nude women drape themselves over Cutting. Amsterdam has sex with Jenny (she isn’t nude, but the depiction of their activity is graphic). Worse, their intercourse is preceded by an angry altercation. Later, Cutting sneaks into their room and watches the two sleeping. When Amsterdam wakes up, Cutting make a vulgar reference about them having had oral sex. A man dressed as a woman lines up with the rest of the ladies at a dance.

• violent content: The violence in Gangs of New York is so pervasive and graphic that to itemize it all would be at best nauseating. What struck me throughout the nearly 3-hour film was that nearly every social gathering triggered some sort of brawl or riot. Various police forces fight one another more than they fight crime. Competing fire departments battle each other while untended buildings blaze beside them. Dances turn into dirges as dead bodies pile up. Politicians make public speeches, and if someone doesn’t like what they have to say, they murder them in the doorways of their own homes. Blood flows thick on the cobblestone streets as flesh is pummeled with axes, spears, knives, clubs, bullets and bricks. Dozens of scenes include gore. One, so extreme I’m compelled to mention it only in the broadest strokes, shows The Butcher ripping a man’s intestines from his belly and dumping them on the floor. Arms are severed. Bones broken. Throats slit. Skulls split. Chests impaled. Cannon fire decimates buildings, kills hundreds of people and sets large sections of the city on fire (the billowing smoke that covers Manhattan sends shivers up and down your spine). Four men are executed in a public hanging. More than once, a knife that is plunged into a man’s gut is twisted and turned to cause as much damage as possible. A dead man is hung on a makeshift cross for passersby to see. Amsterdam’s face is branded with a red-hot knife blade.

• crude or profane language: Six f-words (one of them used to reference sex) and one s-word. A dozen milder profanities are all but drowned out in the din, but the same number of profane uses of the Lord’s name stand out starkly (seven or eight times, characters abuse the names "Jesus" and "Christ").

• drug and alcohol content: Drinking is common. Several scenes are shot in pubs and at wild parties. Amsterdam and others in Cutting’s gang smoke an unnamed drug from a long pipe. Amsterdam and Cutting smoke cigars and pipes. Others smoke cigarettes.

• other negative elements: Men wager on everything from brutal boxing matches to animal fights. When Vallon is about to die, he holds his young son’s head in his hands and forces him to watch as Cutting turns the knife in his gut. One of the men who is hanged calls out to his watching son and entreats him to watch. Both of these scenes are used to communicate an intense commitment to avenging loved one’s deaths, a mission Amsterdam devotes his life to. In contrast, God tells us that vengeance is His, and that we are to trust Him with our lives and with our death (Romans 12:19). Racism rears its ugly head repeatedly in the film. Epithets are hurled against Blacks, Chinese and other immigrants. Such sentiments and the cruel behavior it inspires aren’t condoned in the story; neither are they condemned. They just are. Politicians set a disturbing example, clinging to popularity and power rather than truth and ethics. "The appearance of the law must be upheld," declares one such man of considerable sway, "especially while it is being broken." Citizens are forced to vote (sometimes more than once, and at the point of a knife) for the candidate with the most devoted henchmen.

• conclusion: Oddly enough, Gangs of New York was shot in Rome. The ancient streets and teetering tenements found there made a perfect backdrop for 19th century New York. "We cocooned ourselves in this little environment," Leonardo DiCaprio said. "We woke up every day and went on set and went back in time." That commitment to authenticity and realism radiates from every nook and cranny of the film. As Daniel Day-Lewis is apt to do, he completely loses himself in his role as The Butcher. It’s one of his most distinctive roles yet, and he’s had a lot of them. DiCaprio has fully rebounded from his Titanic slump, giving Amsterdam layers of complexity and conflicted nuance. He’s at his best when tormented by the fact that his desire for revenge is softening under an inscrutable affection for his enemy. "I’ve been taken under the wing of the dragon," Amsterdam mutters. "And I’ve found it to be surprisingly warm."

The history lesson proffered here is well taken. I’ll leave its accuracy for the historians to debate, and suffice it to say that I walked away more grateful than ever for my cushy 21st century life. What’s missing from New York in 1863 is the rule of law. And that makes all the difference. Today we thrive in a society governed by law and order to be envied by all other countries, and this movie makes one immensely grateful for that. If the actual events of Civil War New York were only one-fifth as frightening as what emanates from Scorsese’s imagination, not many of us would dare wish its return.