The assertion that 'all men are created equal' was of no practical use in effecting our separation from Great Britain and it was placed in the Declaration not for that, but for future use.

The quote "The assertion that 'all men are created equal' was of no practical use in effecting our separation from Great Britain and it was placed in the Declaration not for that, but for future use" by Abraham Lincoln reflects his interpretation of the purpose behind the famous phrase in the Declaration of Independence. Lincoln suggests that the phrase, though crucial for articulating the ideals of liberty and justice, was not immediately necessary for the American colonies' break from Great Britain. Instead, it was strategically included as a foundational principle to be used in the future as the nation would evolve and confront issues such as slavery and civil rights.

The origin of this quote comes from Lincoln's thoughts on the broader implications of the Declaration of Independence during his presidency, particularly in the context of the Civil War and the Emancipation Proclamation. Lincoln believed that the principles of equality embedded in the Declaration were initially idealistic but would become the driving force for social change and the abolition of slavery in the United States. This statement is part of his vision for a nation that lived up to its foundational ideals.

In this context, Lincoln’s statement acknowledges that the revolutionary goal of separating from Great Britain was more about political independence than the implementation of equal rights. However, he recognizes that the phrase "all men are created equal" was a timeless and powerful ideal that could be used to challenge the injustices of the future, particularly in the fight for freedom and equality for all citizens. The statement also highlights Lincoln’s understanding that the Declaration served not just as a document for independence but as a moral framework for the nation's progress.

Ultimately, this quote underscores Lincoln's belief in the Declaration of Independence as a living document, whose principles would eventually serve as the basis for social reform and legal equality. While the phrase may have had little practical application during the nation's early struggle for independence, Lincoln saw it as an essential tool for the future of America, as the country moved toward fulfilling the promise of equality for all people.