February 21, 1908, Auditorium Hotel, Chicago."

Photographer Geo. R. Lawrence
The photograph shown above is a copy of a copyright photo on file in the Library of Congress, as entered by the photographer, George R. Lawrence.  As a daredevil balloon photographer in the late 19th and early 20th century, Lawrence not only took the photo (of the three front figures, Lawrence is on the far right) but was also a charter member of the Aeronautique Club of Chicago.
Unfortunately, no information has been found regarding this organization, nor the term Federation of of American Aero Clubs.  But I assume it just means various city clubs that made up the Aero Club of America.

Editors update: quoting from a Feb.5,1908

news article-The Inter-Ocean, Chicago, "Aero Clubs to Meet Here.  Local organization
issues call for convention.  Balloon men from all over country will visit Chicago Feb.21 &22, will effect federation.  (text as follows) "Acting on the suggestions of Augustus Post of New York, secretary of the Aero Club of  America, made in a recent address before the Aero Club of New England at Boston, the officers of the Aeronautique Club of Chicago have issued  a call for a meeting of representatives of the various aero clubs throughout the country, to be held in this city on Feb21 & 22.
     At that time the organization of a federation of Aero Clubs will be effected, officers  elected and by-laws adopted. The benefits of such an organization for the disemination of matters of aeronautical interst and to derive the results of even closer union are obvious.  It was the intention of the Eastern organizations to hold the initial meeting in New York, but this arrangement was objected to by many of the Western Clubs on the ground that the center of aeronautical activity was not in New York or Boston, but in the West."   The article was below a portrait of Geo. R. Lawrence who was identified as the Vice-President of Chicago Aeronautique Club.
My reason for listing this photo is to try and identify as many of the attendees as possible.  Unfortunately the original print is apparently in poor condition and the copy neg doesn't help.  So this is what we have to work from.
I hope that anyone who views this photo and knows anymore about this function at this time, or the Aeronautique Club of Chicago, will send me the information to post on this site.
Walter Wellman
Lower R/corner?

Please contact Tom Yanul for any questions,answers or just to chat about this subject
Lawrence(standing dark suit) with ill-fated rotary wing design.
Lawrence in Minnesota  doing aerial photos for Minneapolis Tribune Paper.
The Lawrence B-2 at Lake Calumet
guarded by Harold Brownell-1917
For additional info on Geo. R. Lawrence and his heavier than air
work take a look at   the following page