Adam Clarke on Romans 5:13

For until the law sin was in the world - As death reigned from Adam to Moses, so also did sin. Now, as there was no written law from Adam to that given to Moses, the death that prevailed could not be the breach of that law; for sin, so as to be punished with temporal death, is not imputed where there is no law, which shows the penalty of sin to be death. Therefore, men are not subjected to death for their own personal transgressions, but for the sin of Adam; as, through his transgression, all come into the world with the seeds of death and corruption in their own nature, superadded to their moral depravity. All are sinful - all are mortal - and all must die.