The public celebrations of the Columbian Centennial likewise advanced the goal of assimilating immigrants into a single American identity. The 1892 Columbus Day parade in New York City displayed "the flower and the fruitage of the civil and religious liberty of the American republic," wrote Martha J. Lamb. She was particularly pleased to see that "children who were the descendants of the peoples of every nation, marched under one flag, the Flag of the United States...growing up to be educated American citizens, no matter what might be their creed or their origin."

But neither Italians nor other Catholics were prepared to cede such a powerful symbol of their own identity, any more than they were willing to abandon their own particular heritage and beliefs. They wanted Americans to be treated equally, whether of Irish, Italian or Anglo-Saxon descent. They pushed for a new form of American identity, pluralistic enough to allow their children to retain their own creeds and origins and still be accepted as patriotic Americans.

At the forefront of the struggle came the Knights of Columbus. Founded in 1882 as a Catholic alternative to the popular fraternal orders of the day, its first generation of members was almost exclusively Irish. Yet they took Columbus as their namesake, embracing the appeal of America's most popular Catholic as a means of forging a cohesive Catholic community. In grand Columbus Day parades, they asserted their own patriotism and respectability, proudly affirming that good Catholics could also be good Americans.

Out in Colorado, an Italian immigrant named Angelo Noce relentlessly pushed legislation to transform the local observances of the Italian community into a formally recognized holiday. In 1905, he succeeded. There was nothing remotely like it on the civic calendar of the era. The Governor's proclamation declared Columbus Day:

a day upon which maybe gratefully recognized the patriotic Americanism of the Colorado Italians whose generosity prompts them to present to the state an emblem of appreciation of the services to mankind of one of their countrymen, and a material evidence of the good citizenship of those Americans who belong to the same race as he did.

Local papers celebrated it as an important step in combating prejudice and bigotry, but it was much more. It served as a formal acknowledgment that immigrants could preserve their own ethnic identities and simultaneously embrace their new nation. Two years later, it became a statutory holiday. Over the ensuing decades, the Knights of Columbus pressed the cause in other states, with widespread success. In 1934, Congress voted to recognize Columbus Day as a federal holiday.