Baltimore native Joe Odoms had been singing the national anthem at Ravens home games since 2014.
On Tuesday, the member of the Maryland National Guard who served tours of duty in Afghanistan resigned.
In an Instagram post, Odoms wrote: "The tone/actions of a large number of NFL fans in the midst of our country's culture crisis, have convinced me that I do not belong there."
His decision to leave came two days after several Ravens — including retired linebacker Ray Lewis — took a knee during "The Star-Spangled Banner" before a game against the Jacksonville Jaguars in London.
Every NFL game over the weekend featured some form of protest or demonstration of unity, as players, coaches and team owners stood with their arms linked during the anthem. Three teams — the Pittsburgh Steelers, Tennessee Titans and Seattle Seahawks — stayed off the field during the anthem.
Renewed attention was focused on NFL players during the national anthem after President Trump said Friday night that players who kneel or otherwise take part in protests during the national anthem prior to games should be fired.
It was 203 years ago, not far from where the Ravens play at M&T Stadium, that Francis Scott Key penned the poem that would become the national anthem. Key wrote "The Star-Spangled Banner" after watching Fort McHenry withstand an attack by British ships on Sept. 14, 1814.
Odoms' Instagram post said, "This is not an emotional reaction to recent events, rather an ethical decision that part of me regrets but my core knows is the right choice."
"We greatly appreciate the work Joey did for us and we thank him," Ravens senior vice president of public and community relations Kevin Byrne said to The Baltimore Sun.
The Sun also reports:
"A member of the Maryland Army National guard, Odoms succeeded longtime Ravens' anthem singer Mishael Miller, who relocated to Alabama after the 2013 season.
"Odoms, a songwriter and former 911 operator who grew up in Reservoir Hill, beat out eight other finalists for the job of singing 'The Star-Spangled Banner' before Ravens home games.
"He initially expressed interest in the job directly to Ravens coach John Harbaugh. The two met when Harbaugh was visiting the base Odoms was stationed on in Afghanistan in February 2013."
Odoms thanked fans "for allowing me to live out a dream of sharing my gift with you."