The Supreme Court on Monday rejected hearing a case that challenges the use of Confederate imagery in the Mississippi state flag.

Carlos Moore, an African-American attorney from Mississippi, argued that the flag represents "an official endorsement of white supremacy."

"The message in Mississippi's flag has always been one of racial hostility and insult and it is pervasive and unavoidable by both children and adults," Moore said in his court appeal.

"The state's continued expression of its message of racial disparagement sends a message to African-American citizens of Mississippi that they are second-class citizens."

The justices did not comment on their decision to decline Moore's appeal to have the flag ruled as an unconstitutional symbol of slavery, The Associated Press reported.

"We always knew it was a long shot," Moore told the news wire.

After a lower court rejected the lawsuit for lack of standing in April, Moore appealed the case to the Supreme Court on the grounds that the U.S. Court of Appeals for the Federal Circuit had given the 14th Amendment's Equal Protection Clause too narrow of an interpretation.