At the onset of the 20th century, the United States was not the most welcoming country to Chinese immigrants. From the Chinese Exclusion Act to yet more blatant racism, Chinese Americans were unable to find jobs, had to establish Chinatowns where their families could live peacefully, and still had to always pledge their unwavering patriotism to the United States, lest they risk further social ridicule.
However, this all changed on December 7, 1941, when the Japanese launched a surprise attack on Pearl Harbor, killing 2,000 American soldiers and injuring 1,000 others, spurring the United States's involvement in World War II. Yet, for Chinese Americans, this suddenly meant they were no longer viewed as the enemy. Rather, the US and Chinese immigrants now shared a common enemy: Japan.
In order to further establish their loyalty to the United States - as well as to protect themselves from the brutal surge in racist violence and forced internment to which Japanese Americans were suddenly being subjected - Chinese Americans began to wear signs, pins, and flags declaring their Chinese descent and in some cases became active participants in the racist culture that had erupted in the US since the Japanese attack.
As soon as Chinese families began immigrating to the United States during the California Gold Rush in 1848, social tensions began to run high. Discrimination against people of Chinese descent became the norm as they were viewed as intruders who came to the US to take jobs from other American citizens. They faced joblessness, exclusion, political and legal discrimination, and physical confrontation.
So, once the Japanese began to draw the focus of US ridicule after the surprise strike in Hawaii, Chinese Americans were subjected to less discrimination. With China becoming a new ally to American efforts in WWII (and with Japan being a common enemy), Chinese-American pride began to expand. In an effort to further deflect discrimination, Chinese Americans began to wear signs and pins, and carry flags with them to clearly display their Chinese heritage and avoid being mistaken as Japanese.
As the US entered into WWII and tensions with Japan continued to rise, Chinese Americans and even Chinese newspapers in the United States adopted some of the discriminatory anti-Japanese rhetoric deployed by much of the rest of the press.
This led many Chinese Americans to become passive to the prosecution endured by their Japanese neighbors on US soil, and in many cases they even took over the jobs and shops that had been abandoned by interred Japanese.
Just as the stage was being set in Europe for the rise of Adolf Hitler and the eventual conflict that would become WWII, China was continuing its own battle with a neighbor, Japan. Conflicts between China and Japan go back for generations; however, at the beginning of the 1930s, these historic tensions began to take a turn for the worse as Japan sought to assert its control over Chinese territories. In 1937, China launched a full-scale resistance against Japan, known as the Second Sino-Japanese War.
This resistance quickly fell into a lull as the Chinese struggled to regain their territories from Japanese control. Yet, when Japan struck against the United States, they also pushed the western superpower into a political alliance with China. This meant that the United States would begin providing aid to China to help defeat their now common enemy - and meant that Chinese sentiments in the US were, for the first time, on a huge upswing.