Before I say this, let me say that copying someone else's data into your database is not advised at all.
But at least make certain it makes sense before entering it into your database. I saw an online family tree where the mother and father died before their children were born and another couple who had their children before they (the parents) were born. Woah!
And if your database indicates someone died in 1742 and served in the American Revolution something is decidedly amiss.