After considerable coverage by many media outlets, Atlantic City's 1920s era underbelly has been more than adequately exposed. The stories of the brothels, illegal gambling, prohibited liquor sales and public corruption of that era have been well told by Nelson Johnson in "Boardwalk Empire" and by many other writers. But, there is a lesser known story about that era that will not be understood by the millions of Americans who will tune in to HBO's dramatization of "Boardwalk Empire." Was Atlantic City all about political corruption with mobsters vying for control of prostitution, gambling and alcohol sales? The answer is a resounding no; it was a broad commercial success that practically invented an industry.

While "Boardwalk Empire," the TV series, will undoubtedly showcase the "adult entertainment" available in Atlantic City in the '20s and '30s, the city was much more than that. It was a commercial success with successful banking, robust retail and a very active, 1,500-member Chamber of Commerce. Of course, the major industry was hospitality, and millions were drawn to Atlantic City to enjoy its healthful and thrilling entertainment options, but not to be overlooked - legitimate business activity was key.

Approximately 15 million visitors a year made Atlantic City (after Niagara Falls) the second most popular destination of its time. Interestingly, 15 million annual visitors represents approximately the same proportion, (10 percent), of the U.S. population as visit Atlantic City today. The fact that, on a proportionate basis, Atlantic City is as popular an attraction as it was in its "glory" years will surprise many. In the 1920s, Atlantic City certainly enjoyed a distinct advantage as a well known "open town" that attracted tourists for amenities that could be enjoyed in very few, if any, competitive destinations. But, more importantly, the city practically invented the modern convention business.

Approximately 300,000 delegates attended 300-350 conventions a year in Atlantic City during the 1920s. Once the largest convention center in the world was opened on the Boardwalk on May 31, 1929. It alone handled close to 200 conventions/events in 1931. The depression of the 1930s gradually eroded the count to about 80 by 1938. The $15 million convention center was opened by Mayor Anthony M. Ruffu, who introduced U.S. Sen. Walter Edge, who then introduced the keynote speaker, Vice President Charles Curtis. Thousands of delegates of the National Electric Light Association went on to hear a speech by Thomas Edison who spoke of the opportunities presented by "light."

Estimates at the time were that on a hot summer weekend more than 50,000 bathers were on the beach enjoying the water and fresh salt air, a number that is not much different than you would find on a Saturday this summer, despite today's ubiquity of air conditioning. If anyone wanted to buy beachfront property, the 1920s price was approximately $400,000 an acre. Adjusted for inflation, that amounts to approximately $5 million in 2010, an amount that is close to what an acre of beachfront fetched at least until a few years ago before the recent economic downturn. The total assessed value of Atlantic City at the time was about $200 million; that's equivalent to about $2 billion today. The actual assessed value today is close to 10 times that amount. For those who are curious, Bader Field was assessed at about $3 million in the 1920s.

Most arrived in the city by one of three trains. The round trip cost from Philadelphia was $1.50, not much different than today's adjusted for inflation cost. In the summer, 100 trains a day pulled in to one of three stations along in the center of town.

Beyond the approximately 20 major boardwalk hotels, four of which still stand (Resorts, Ritz-Carleton, Claridge and Dennis), visitors had a choice of 1,200 hotels and comfortable rooming houses which could accommodate almost 400,000 guests. Guests, whether attending conventions or on vacation could enjoy magnificent live shows around town or on one of the six piers or 21 theaters.

While many clearly came to Atlantic City during Nucky's era for the "booze, broads and gambling," millions of others, business travelers and vacationers, were attracted by the fresh beach air, exciting entertainment and first-class accommodations, just the right formula for Atlantic City as a 21st century tourist destination.

Israel Posner is executive director of the Lloyd D. Levenson Institute of Gaming Hospitality and Tourism at the Richard Stockton College of New Jersey.