The first "I Am An American Day" parade in Baltimore started at Thirty-third Street and The Alameda on May 17, 1942. The event (and similar marches and rallies across the country) was promoted by the Hearst Corporation, then owner and publisher of the Baltimore News American newspaper, as a way to celebrate the U.S. Constitution. Some accounts suggest the initial idea for "I Am An American Day" came from Arthur Pine, head of a New York public relations firm, after he was asked to promote a new song, “I Am An American,” by Gary Gordon. In 1940, William Randolph Hearst succeeded in pushing the U.S. Congress to name the third Sunday in May as “I Am An American Day” as a way to recognize immigrants who had received U.S. citizenship. The date was moved to September 17 in 1952 and, in 2004, an amendment by Senator Robert Byrd led congress to rename the event from “I Am An American Day” to “Constitution Day.”
In Baltimore, the annual parade moved to the streets around Patterson Park and quickly began to draw thousands of participants. The 1944 march saw an estimated 23,000 people. The next year, around 75,000 people came out to see 100 groups of marchers along with 50 "bands and drum, fife and bugle corps" By the 1970s, the parade had steady attendance from church groups, veterans organizations, and politicians developed into what the Baltimore Sun writer Liz Atwood later called "an opportunity for Baltimoreans to show their pride in being Americans." By the mid-1990s, the parade followed a naturalization ceremony for new citizens. Over the years, special guests at the parade included actors from popular soap operas and Hollywood movies. Huge crowds gathered for the route to watch and hear local high school marching bands and out-of-town draws like the Philadelphia Mummers Quaker City String Band. At the parade's height, the event drew over 300,000 people and lasted four hours or more.
In 1975, Maryland Institute College of Art photography professor Linda G. Rich was among the crowd. According to the Maryland Historical Society, Rich was new to Baltimore and was "struck not only by the patriotic display of the celebration but by the unique characteristics of the surrounding neighborhood: the rows of clean, white marble steps, the vibrant painted screens, the window displays full of religious and patriotic iconography." The next year, Rich, along with her students Joan Clark Netherwood and Elinor B. Cahn started what became the four-year-long East Baltimore Documentary Photography Project that captured over 10,000 photographs capturing the area's strong sense of community and unique identity.
Southeast Baltimore has changed in radical ways since the 1970s and the "I Am An American Day" parade changed as well. Unfortunately, in 1993, the city's effort to raise fees for the event led parade organizers to threaten to move the event away from Highlandtown and Patterson Park. Edwin F. Hale, Sr., then chairman of Baltimore Bancorp, wrote a check to cover that year's extra expenses but, in 1994, no other benefactor came forward and organizers moved the event to Dundalk in southeastern Baltimore County where it continues to be held through at least 2014.