Female dancers performing the Charleston, 1926. (Scherl / Sueddeutsche Zeitung Photo/The Image Works/PBS)

Honoring the Volstead Act’s ultimate lesson, I now forbid you to watch “Prohibition,” Ken Burns and Lynn Novick’s latest epic historical documentary. Which will, of course, have the reverse effect of making you want to watch it even more. That’s “Prohibition’s” lone and oft-repeated take-away: Americans don’t like being told what to do.

The 18th Amendment, which banned the sale of alcoholic beverages between 1920 and 1933, was a disastrous experiment in government attempting to enforce morals, and it was, in the opinion of “Prohibition’s” many historians and cultural critics, the only time the Constitution was used as a way to limit freedom instead of promote it.

Viewers who stay for all five-plus hours of “Prohibition” will stagger away filled but not necessarily satisfied. The era is ripe with many historical-social corollaries and outcomes, and it could not be a more tailor-made subject for America’s Greatest Documentarian. Prohibition is inextricably linked to politics, the suffrage movement, religion, the South, civil rights, immigration, jazz — just a few of Burns’s favorite things. It is packed with bigger-than-life characters who left behind a lot of stirring words and a surplus of photographs and movies. If this documentary were made of alcohol, it could be chugged out of beer bongs at a Ken Burns frat-house blowout.

Some viewers will — and should — stop after a sip or two. Those of us who have watched Burns’s many masterly works over the years will recognize the trademark moves: the graceful pan-’n’-scan over archival photos and documents; the surprise treat of high-end celebrity voices reading bits of correspondence and arguments; the soundtrack choices resonating into redundance.

Burns’s fans will also await a magical moment that almost always occurs in his work: The epic scope of it eventually takes hold and you become far more absorbed in the subject than you ever thought possible; it’s a moment when you stop to realize that you are learning.

Women spurred the early temperance campaigns but eventually led the movement to end Prohibition, after its failures became obvious. A ‘Crusader’ poses in 1930. (Library of Congress/PBS)

This has happened to me with his now-legendary takes on baseball and jazz — two subjects I’m not opposed to but also not naturally obsessed with. Once you’re in — once Burns has you hooked — you’re in for the long haul. I got to the end of 2007’s “The War” with something akin to the tingling high that marathon finishers must feel. I even stayed in for the whole of 2009’s “The National Parks: America’s Best Idea,” which was too long by half.

Burns has the similar gift of that rare history professor who can captivate even the most reluctant student by bringing the material to life. Thus, he is much beloved all across campus by everyone except other history profs. His tenure is unassailable.

Which makes me sad to note the long stretches of sober boredom in the middle of “Prohibition,” even though it is short (three nights, beginning Sunday) by Burns’s standards. At one point, I considered watching the documentary while drunk, to see if it improved. (It might help my writing, too.)

“Prohibition” draws on journalist Daniel Okrent’s comprehensive 2010 book, “Last Call.” Part 1 is called “A Nation of Drunkards,” and it is by far the best part of the project, exploring the nation’s colonial and pioneer dependency on booze, which was terrifying. When admiring our forebears’ survivalist resolve, we have to admit just how drunk they were on a daily basis. “Prohibition” eloquently grieves the toll this took on women and children, who lived in the fearful presence of abusive men who drank three times as much as today’s casual imbibers. The degree to which the United States drank in the 18th and 19th centuries is simply astonishing and goes a long way to explain the forces from which the temperance effort emerged, as well as the moral logic behind it.

The second episode — “A Nation of Scofflaws” — loses steam just when the buzz of it all should really kick in. As a smart publicity move, “Prohibition” has attempted to ally itself with the freshly arrived (and suprisingly vigorous) second season of HBO’s “Boardwalk Empire,” which is set in Atlantic City during Prohibition. The two seem to be a natural fit, appealing to viewers who will never tire of stories about mob violence. The prohibition portion of “Prohibition” — the gangsters and crime and dirty politics — should be the most exciting part, describing what it was like on the day the booze flow stopped in 1920 and a criminal network immediately rose from grass-roots moonshiners to a deadly cartel that controlled shipping and handling.

Thanks to the emerging prevalence of movie cameras by then, Burns and his trusted collaborator, Novick, make use of much footage — too much — that shows men with picks and axes hacking away at barrels of beer and grain alcohol. Again and again and again. The talking heads begin to drone on, less profound this time, not brimming with the same wonder seen in the experts Burns has assembled in the past.

It’s rare for Burns and Novick to get lost in their own material, but it happens here. In trying to show the reach of Prohibition, the film gets distracted by the era’s many parallels. At one point, it could have just as easily been a fascinating documentary about sexual liberation. At another point, it could be a movie about the American economy and the Great Depression. (Next up for Burns and company, by the way, is a project due next year called “The Dust Bowl.”) All of it is relevant, but none of it quite coheres.

If Parts 2 and 3 (“A Nation of Hypocrites”) could have somehow been as revealing as Part 1, then “Prohibition” might have equaled “Jazz” and “Baseball.” Something I always long for in Burns’s project is something he avoids on principle, which is to link the past to the pres­ent. His sense of denouement and epilogue always feels hurried and tacked on — in “Prohibition’s” case, this means a quick nod to such movements as Alcoholics Anonymous but no correlation to “just say no,” the drug wars, the Mexican cartels or the effort to legalize marijuana. In our current cultural and political skirmishes we often gravitate toward legislative impulses that would force one person’s morality on another, but Burns isn’t going there. He is never about the now.

Better, then, to focus one’s 1920s fixations on the dark duplicity and bitter heart of “Boardwalk Empire,” which is two episodes into what looks to be an even better season than the first.

The preoccupying arc this time is to make Steve Buscemi’s Enoch “Nucky” Thompson’s life a little more hellish as he staves off bootlegging competition and personal betrayal from all sides. To its array of lowlifes, “Boardwalk Empire” has added the Ku Klux Klan and is giving intriguing dimension to my favorite character, Margaret Schroeder, played by Kelly Macdonald. Charlie Cox (Ishmael from Encore’s recent “Moby Dick”) has joined the cast as Owen Slater, an Irish tough with a charming smile.

“Boardwalk Empire” gets so gravely serious, and its men are so thuggishly repugnant by design, that a smile like Owen’s goes a long way toward adding some spark. “Boardwalk Empire” is doing what I wish “Prohibition” had done — it’s tempting me to stick around for one more.


(five hours over three nights) begins Sunday at 8 p.m. on WETA and MPT. Parts 2 and 3 air Monday and Tuesday at 8 p.m.

Boardwalk Empire

(one hour) airs Sundays at 9 p.m. on HBO.