Before the introduction of home mail delivery, slaves often carried letters to and from the post office. Slave-carried mail is usually identified by a notation—called an endorsement—that also served as a travel pass. These mail messengers could be an important source of news if they overheard discussions during their travels. Slaves sometimes carried letters directly to the recipient, bypassing the postal system entirely. This was often the case when the letter was accompanied by a parcel, since post offices did not handle domestic package mail until 1913.