The American Red Cross’s poster included an image showing black people engaging in inappropriate behaviour at a swimming pool.
Margaret Sawyer was traveling with her family in Colorado when she noticed the poster on two separate occasions.
She said: "When I saw the poster, I just, was just very saddened that the Red Cross had chosen to put out an image that might one, discourage African-Americans from trying swimming if they were new to it, and also something that would extend a negative stereotype.
"How can an organisation that prides itself on being so open-minded, so understanding of the diverse populations of the world create something like this?”
The poster appeared to label the actions carried out by the black children in the cartoon, such as diving and pushing other children, as “not cool”.
While some immediately acknowledged this as a problem, others failed to see what was racist about the poster, calling it an example of politic correctness gone awry.
Ebony Rosemond, who leads the organisation 'Black Kids Swim', told the Washington Post: “The current state of affairs is unfortunate, and images like the one created and circulated by the red Cross make things worse.
"In connection with the lack of images showing African Americans excelling in swimming, the post doesn’t make you feel welcome - it suggests to a black child that you’re not welcome here."
The Red Cross has since apologised on Twitter and made a public statement claiming that causing offence was never intentional.
The statement read: "The American Red Cross appreciates and is sensitive to the concerns raised regarding one of the water safety posters we produced. We deeply apologise for any misunderstanding, as it was absolutely not our intent to offend anyone.
“As one of the nation's oldest and largest humanitarian organisations, we are committed to diversity and inclusion in all that we do, every day.”
The Red Cross responds to approximately 70,000 disasters in the United States every year, ranging from home fires that affect a single family to hurricanes and earthquakes.
It provides shelter, food, health and mental health services to help families and entire communities get back on their feet.
The organisation also supports American’s military families, is the nation’s leading provider of health and safety courses, such as CPR, Firs Aid and Lifeguard training and is the largest single supplier of blood and blood products in the U.S