According to lincoln, how does a nation make sure that free governments (democracies), "shall not perish from the earth"?

He is saying that every generation must work to preserve what was fought here and remember the sacrifices made during that day.  They gave their lives not only to protect the Union but also for the liberties of all men so everyone would be equal.  This is the best way to ensure that democracy will always be there.

one of the main reasons was definitely slavery. back in 1861, republican abraham lincoln was elected and ended up being a major influence in the slavery business. slavery greatly affected the texas economy because back in 1845 during the annexation of texas, slaves became a big part of the texas population. many texans that were in favor of the secession influenced groups through party ties.

the answer is to stop cheating on plato