In the fall of 1920, a group of Sioux City war veterans met to form a band. The eight musicians were all members of the newly organized Monahan Post of the American Legion in Sioux City and many had just returned from the battlefields of World War I. Herman Koch, Commander of the Monahan Post, believed a band would strengthen the post and he put out a call for musicians. They began to practice under the baton of director Barney Flanagan, a barber who had been a bandmaster in the Army.
Some of the men were experienced musicians, others were novice players, but they all brought great enthusiasm to the job. Before long, they had boosted their numbers to twenty men, and Harry Johnson, just returned the battlefields of France, assumed the director's role.
The Monahan Post News of December 8, 1920 declared: "So we got down to good honest-to-God work and we got a band, and boy, she's some band. They've got the goods."
Several of the musicians had been members of the Sioux City Journal's Newsboy Band, which was organized in 1912 for newspaper carriers. World War I sent many of those boys overseas. Upon their return at the end of the war, some of them became charter members of the Monahan Post Band.
Over several months, the Monahan Post encouraged able members to join the band. "Come on brother, if you are not in the band, and you think you can toot a horn, drag along that old instrument to rehearsal every Thursday night at the Club rooms, and let us know that you are one hundred percent booster." Members included a barber, a garage man, newspaper reporters, journalists, clerks, a very few professional musicians.
Olive drab uniforms were purchased and worn for the band's first public concert on May 29, 1921. The new band played their first concert in the Central High School Auditorium in front of a small group of friends and supporters. Despite the disappointing crowd, the Sioux City Journal pronounced the event a "triumph", and related: "From every point of view, their playing was excellent, and it was difficult to realize that this was their first appearance." It was just the first of many triumphs for Sioux City's renowned American Legion Monahan Post Band.
The band began to get organized. They adopted a set of by-laws, elected officers, and designated a librarian and a property manager. Regular rehearsal times were set and "the penalty for tardiness" was set at twenty-five cents for each offense.
During the summer of 1921, the band grew in popularity and received frequent requests to play. With growing confidence, they attended the National American Legion convention in Kansas City and entered their band in competition with one hundred other Legion bands. They competed for the $1000 prize with enthusiasm, not really expecting to win anything. The musicians were pleasantly surprised when the judges announced that they had tied for third place. Encouraged, the band resolved to make a serious effort at competition in the future. Immediately, their slogan became "New Orleans or Bust".
The Monahan Post Band focused on their next competition in New Orleans. The business community donated to a band fund, which helped meet expenses, and the group grew to forty-five men. They left Sioux City on a special train, dressed in "snappy new uniforms". Then, on October 18, 1922, in New Orleans, the band won first prize and the title of "Official Band of the American Legion", a title they held for many years. The band was awarded $1000 in cash, a silver cup, gold cornet, silver-mounted snare drum and citation for meritorious service. It was the beginning of local fame and international prominence. They became well known for playing Karl King's march, Barnum and Bailey's Favorite, one of the numbers that helped them claim first prize in New Orleans. The composition became closely associated with them, and they even made a recording of it. The band continued to win first place honors at St. Paul (1924), Omaha (1925), Philadelphia (1926). In 1924 James A. Melichar replaced Harry Johnson as conductor.
In 1926, the band went to Chicago for a recording session with Victor Talking Record Company. The recording included: The Iowa Corn Song, The Conqueror's March, Barnum and Bailey's Favorite March, and March Salutation. An article in the Phonograph Monthly Review reviewed the recordings: "Several months ago two remarkable records were released by the Victor Company of the band of the Monahan Post, Sioux City, American Legion. Their merits were given due praise not only in these pages but also abroad by the noted band-reviewer W. A. C: "The band is a very fine one. The Iowa Corn Song is made into a very jolly affair and the singing of the bandsmen is more lusty and hearty than is usually heard. The Conqueror is an invigorating march played with plenty of spirit'an American recording in the same class with Sousa and Pryor recordings, which is high Praise indeed."
The band went on to win a total of seven first place prizes at American Legion Competitions, but many considered the high point to be the competition in 1927 in Paris, France. The trip seemed like an impossible expense until the Iowa Legislature appropriated $50,000 to help finance the trip for the Monahan Post Band, the Fort Dodge Drum and Bugle Corps and the Davenport Auxiliary Corps. The Sioux City band received $22,500 of the funds, which made the trip feasible.
Newspaper accounts estimated that over one million French citizens lined the six-mile parade route to watch the bands parade through the streets. At the head of the parade was Sioux City's own Monahan Post Band. "The Sioux Cityans led the convention parade down the Champs Elysee and through the Arch of Triumph." When they received the word that they had won First Place, the band burst into a rousing rendition of the "Iowa Corn Song".
From 1928 until 1932, the band did not look for funding to appear at National conventions. The nation was in the midst of The Depression, and business conditions could not support such an effort. When conditions improved, the band entered the 1933 competition in Chicago and took second place. In following years, they posted first place victories again in Chicago in 1939 and Boston in 1940.
In Sioux City, the Monahan Post Band was legendary for their summer concerts in Grandview Park. They performed on a platform in the park, attracting sizeable crowds. In 1930, shortly after Leo Kucinski became the director, the band began to campaign for a music shell to be erected in the park. As a result of their efforts, the Grandview Band Shell was built.
The Sioux City Tribune stated, "The superb record of Monahan Post Band was the inspiration for the successful quest of state and federal support toward building the music pavilion, whose magnificence is second only to the Hollywood Bowl."
The Band Shell was dedicated in 1935 and remained the home of the Monahan Post Band until 1948. At that time, the band ceased its association with the American Legion and became the Sioux City Municipal Band. The Municipal Band continues to play summer concerts in the park.