(CNN)Even during the 1918-1919 influenza pandemic, some Americans were not fans of wearing masks.
They risked hefty fines by refusing to wear them and sometimes ended up in jail. In one case in San Francisco, an organized group called the "Anti-Mask League" held a protest in a local ballroom that was attended by about 2,000 people in January 1919.
Still, there are important differences between the opposition to masks in 1918 and what we are seeing during the 2020 coronavirus pandemic in America, according to historians CNN spoke with.
The "Anti-Mask League" protest in San Francisco "was an orderly protest compared to people fighting in Walmarts today," said Dr. Howard Markel, a medical historian and a physician who leads the Center for the History of Medicine at the University of Michigan.
Just last month in Michigan, the day after Gov. Gretchen Whitmer imposed a mask mandate, a man was shot dead by police after stabbing a male customer in a dispute over not wearing a face mask in a store.
"Today, the anti-mask sentiment has a virulence and violence of its own that we didn't see back then," Markel told CNN.
The 1918 influenza pandemic killed an estimated 675,000 Americans, according to the CDC. At the time, public health authorities and groups like the American Red Cross strongly recommended that Americans wear face masks to curb the spread of the virus, along with following social distancing guidelines and practicing proper hygiene.
In 1918, "lots of people grumbled about wearing masks, or even refused to do so, but they weren't doing so because of a political stance or partisan allegiance," said Alexander Navarro, assistant director of the Center for the History of Medicine at the University of Michigan.
While some people had ideological reasons for not wanting to wear masks, and others saw masks as an infringement on their freedoms, these arguments didn't fit as neatly as they do today in the larger partisan divide.
"The party system a century ago wasn't as heavily aligned along ideological lines, and certainly not along social and cultural issues to the same extent it is today. Today, there are people who refuse to wear a mask out public simply as a way of 'sticking it to the libs,'" Navarro said.
During the war, mask wearing was patriotic
By 1918, the use of masks in medical settings was widespread as more doctors subscribed to germ theory and saw the need to maintain sterile conditions in operating rooms, according to Navarro.
At the time, health officials were aware that influenza was a respiratory disease spread through droplets, so masks were seen as a useful tool to contain the virus. Their use was widely recommended and made mandatory in some cities.