Plzz someonewould president lincoln have been as motivated to pen the gettysburg address if massive numbers of casualties(deaths) hadn’t occurred? why? ( tell me why)

That's an interpretive question that would ask us to get inside the mind of Lincoln from a distance a century and a half away.  We do know that Lincoln long had moral and political objections to slavery.  He had outlined some of those thoughts in a speech given in Peoria, Illinois, in 1854.  But Lincoln's views on what to do about slavery were something that took shape over time.  In the Peoria speech, he suggested that perhaps slaves should be freed in order to be returned to Africa.  But as the conflict over slavery grew and the Civil War became a reality, Lincoln became firmer in seeing this as a struggle not just over preserving the Union but also a battle for human dignity and the principle of equality.   And so in the Gettysburg Address, in 1863, he affirmed the principle stated by the Declaration of Independence, that all men are created equal.  The massive number of casualties at the Battle of Gettysburg certainly gave impetus to Lincoln's words about preserving the Union and government of the people, by the people and for the people.  But those ideas had been central to Lincoln's worldview before Gettysburg as well as in that speech.

He issued the emancipation proclamation. it started changing slavery, and eventually lead to the freedom of slaves.