Abortion- Where does life begin?

In the Declaration Of Independence it states that all men have three inalienable rights. Those rights are life, liberty and the pursuit of happiness. However many people say that abortion, which is legal in The United States, violates the first right. They say that once this baby is conceived and it becomes a sentient that exists in our universe it is nothing less than murder to abort it. However many people claim that it is not a living human until the moment of its birth because it is still dependent on its mother for its continued existence. According to them it is merely a fetus preparing itself for its existence outside of the whom. But where does life really begin? No one has been able to prove either point right, but many people still have very strong opinions.

In my opinion it is astonishing to think how much human life and potential has just been simply aborted. We could have had a great inventor who came up with a more fuel efficient car, or a doctor who found a cure for cancer. Possibly even something like the president or some great leader. But instead they were never given the opportunity to exist. But this page is not all about me, so tell me where do you think life begins???