Sorry about your feels but it is literally written in the 13th Amendment of The Constitution. Slave owners often referred to their slaves as property, not as their slaves. Calling it something else doesn't change what it is.
(bold section I added for emphasis)
Section 1
Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.
Sorry about your feels but it is literally written in the 13th Amendment of The Constitution. Slave owners often referred to their slaves as property, not as their slaves. Calling it something else doesn't change what it is.
(bold section I added for emphasis)
Section 1
Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.