The Declaration of Independence holds no legal standing, neither now or when it was written.
"We hold these truths to be self-evident that all men are created equal, that they are endowed by their creator with certain unalienable rights, that among these are life, liberty and the pursuit of happiness..."
Clearly our governemnt was not founded on these principles, as blacks were kept in chains for almost another 100 years and women didn't receive the right to vote for another 150.