A century ago, Chicago's location made it the nation's fastest-growing city. Now, location is doing the trick again - this time for the city's convention business.
''A hundred years ago, Chicago was the rail center of the country because of its geographic location,'' says James F. Sheerin, chairman of the world's largest convention center, McCormick Place. The railroads are still concentrated here. But now, because air fares are getting so expensive, people are looking at Chicago again because of its central location.''
Mr. Sheerin, a Chicago native who also is senior vice-president of Hilton Hotels Corporation, says: ''People are making mental adjustments because of the economy. . . . They're aware of the cost of living and the cost of traveling, and that's why people (trade show people and convention officials) are checking their demographics and coming here.''
One significant ''demographic'' is that 60 million people live within a 60 -mile radius of Chicago, so the city's location encourages substantial regional as well as national convention business, Mr. Sheerin says.
Dr. Joseph P. Hannon, a former Bostonian who is managing director of McCormick Place and president of the Chicago Convention and Tourism Bureau, says the competition for the Chicago convention dollar is becoming ferocious.
''Chicago is still the No. 1 convention city, but other cities are zeroing in ,'' he says. ''Ten years ago only 15 cities in the country had something called a convention center; now 142 do - not of the dimensions of (McCormick Place), necessarily. But you've got to appreciate the sustenance the hospitality industry has given Chicago. It contributes $2 billion annually, and with the multiplier factor that comes out to $7 billion.'' The multiplier factor is the number of times dollars taht conventioneers spend in Chicago are spent again in Chicago.
Dr. Hannon might be concerned about competition from other cities, but according to his bureau's figures and those produced in a meetings market study by Meetings and Conventions magazine, Chicago is winning.
Even though 1981 was not considered a good year by Mr. Sheerin, his city posted a 105 percent increase from the amount spent five years earlier, compared with a 63 percent spending increase on meetings nationally - a total of $24.857 billion. (Neither the Chicago nor the national figure has been adjusted for inflation.)
In terms of people attending meetings, there were actually 1 percent fewer in 1981 nationally than there were in 1976. By contrast, the Chicago area showed an increase of 13 percent last year over 1976. Of the 65,849,000 people who attended meetings or conventions last year, 2,576,000 did so in or around Chicago.
Dr. Hannon, who assumed his promotional position after serving a year as superintendent of the Chicago public schools, listed reasons to visit Chicago as if he were delivering a sales pitch:
''The friendliness of the Midwest; air access - O'Hare Airport's been closed no more than 10 times in 20 years; 41,000 first-class hotel rooms in hotels, ranging from the gigantic to the intimate; restaurants, from four-star to great-little-ethnic and everything in between; location, location, location.
''What do you want? Shopping? We've got it. Playing? Culture? The Chicago Symphony, the Lyric Opera, the Art Institue. Convention facilities? Not only McCormick Place, but the Expo Center at the Apparel Mart and, out by O'Hare (in the city's northwest suburbs), the Rosemont Horizon and the O'Hare Expo Center.''
McCormick Place is a great, cavernous, steel-glass-and-concrete, flat-topped barn of a building overlooking Lake Michigan, whose exposition space alone totals 760,000 square feet.
The convention center sports the sort of lowest-common-denominator architecture that offends author Tom Wolfe in his recent book, ''Bauhaus to Our House.'' Yet Dr. Hannon finds a great deal of warmth inside its sterile exterior.
''This big building has a fantastic amount of heart and soul. People who work here love it. It works. Last winter, when we were getting wind chills of 65 below, we had heat and all the necessities. McCormick Place is big and functional and its people are professional.'' Including union people? Yes, Dr. Hannon says.
Carl Sandburg's ''city of the big shoulders'' will continue to carry the largest chunk of the nation's convention business, if those paid to boost Chicago have anything to say about it. They will continue to sell facilities and location.
''Obviously, we're not going to get any business from people who want a resort setting.'' Mr. Sheerin says. ''We simply can't compete for that kind of business. But if you're a businessman and you want high attendance at your meeting or convention, and if the demographics show a high concentration of people with access to Chicago, then I think you'll pick Chicago.''
Even so, the city has more to worry about than its climate.
''We've got to get rid of the Al Capone image,'' Dr. Hannon says.