Answer:
The statement "all men are created equal" in the Declaration of Independence was a revolutionary idea at the time it was written, but the reality was that it was not upheld in practice in the early years of the United States. The founders of the country, who wrote the Declaration, were slave owners themselves, and the institution of slavery was deeply ingrained in American society. African Americans, women, and indigenous people were not considered equal under the law, and were denied many of the rights and freedoms that were supposed to be guaranteed by the Declaration.
It took many years of struggle and conflict, including the Civil War and the Civil Rights Movement, for the country to begin to live up to the ideal of equality stated in the Declaration. While there is still much work to be done to achieve true equality in practice, the country has made significant progress in recent decades towards realizing the principles of the Declaration.