According to the USCIS fact sheet, the average annual number of persons naturalizing increased from less than 120,000 during the 1950s and 1960s to 210,000 during the 1980s, 500,000 during the 1990s and to 625,000 during 2000 to 2006.
Citizenship Day itself has its roots in President Woodrow Wilson’s efforts in 1915, where as part of what he called National Americanization Day, the President himself, cabinet members, administration officials as well as prominent public figures such as Supreme Court Justice Louis Brandeis, gave speeches at naturalization ceremonies throughout the nation.