Deliberately omitting essential information needed to understand something is a “lie of omission.” This is a common problem in school, sometimes for understandable reasons like time limitations, other times for bad reasons like pushing a political agenda. Just about every people of any significance in world history has practiced slavery, and been slaves.

This is a picture of some of the books I have on the topic. I have more on my Kindle, more that were not handy, and more I’ve checked out from the library over the years.
 
Non-exhaustive list is here: further down the slavery rabbit hole.

How many of you have heard of the “International Agreement for the Suppression of the White Slave Traffic,” signed at Paris on 18 May 1904? No? Why not?  https://treaties.un.org/doc/Treaties/1951/06/19510621%2010-34%20PM/Ch_VII_7p.pdf

The word “slave” comes from Slav, the ethnic group heavily targeted by slavers in Europe for centuries. The Christian Europeans captured the heathen Slavs, sold many of them to Jewish slavers to be made into eunuchs (most died during the simple but brutal surgery), and then sold to Muslims in the Middle East and north Africa. Nobody has clean hands, or uniquely bloody hands, in the slave trade. Nobody.

The entire trans-Atlantic slave trade, all 350 years of it, would have fueled the Roman Empire’s slave demand for a whole 25 years. The average life expectancy of a Roman slave was less than half of that of a black African slave in Plantation America. It is estimated that the Islamic trafficking of African slaves north involved roughly ten times as many souls as crossed the Atlantic. During much of the 1600s and 1700s an average of about 10,000 white slaves (often referred to today as “indentured servants,” but most were taken entirely against their will, many providing the origin of the term “kidnap,” or were “criminal” children guilty of being poor because of British Enclosure Acts and Vagrancy Acts) were shipped from the British isles to the colonies in the new world, where out of 100 taken aboard ship an average of only 15 survived their first year in the new world. Less than half of those survived the next year. Much of the land growing cash crops was cleared of dense forests by poor white slave-boys who died by the hundreds of thousands before most black African slaves arrived on American shores. A major part of the silk road trade to China and India was white slaves from the west. Islamic slavers in the early 1600s raided up the European coast as far as Iceland. A major item of capture and commerce among the Vikings were slaves, nearly all white, of course. It was mostly coastal black tribes in Africa taking interior tribesmen as slaves, or buying them from Muslim north African slave caravans, for sale to the European slave-traders who plied the African coast. Captain John Smith, of Jamestown fame, and Miguel Cervantes (the author of Don Quixote) were former slaves. The Aztec slaughtered hundreds of thousands of their slaves in ritual human sacrifices, slaves taken in their constant war upon other native tribes. China had a thriving slave trade for nearly all of its history, as do the other Asian countries. Shortly after the Muslim invasion of Spain, a shipment of 3,000 blond-haired, blue-eyed, virgin Spanish Visigoth girls were sent as slaves back to the north African Caliph. Only about 5% of the African slaves traded across the Atlantic ended up in what is now the USA, and they are (on average) the wealthiest group of African-descended people in the world. International slave trafficking was ended by a massive investment by the British navy, using ships mostly manned by involuntarily-serving white men “press-ganged” into service and flogged or executed for any disobedience. Slavery still goes on today… in many places.

Closer to home, a major sticking point for the US when working out treaties with native American tribes was the requirement they give up slavery, which was an essential part of nearly all tribal economies. On the “Trail of Tears,” about 800 slaves owned by the Indians were taken with them to do much of the hard work of moving the tribes; these slaves were a mix of other native Americans, Africans, mulatto, and mestizos. George Washington owned slaves of all races (including white); in fact, white slaves were a majority of slaves in most of the colonies until the late 1700s. The terms “bondsman,” “slave,” “indentured servant,” “servant,” and “indent” were virtually interchangeable when used by colonial and early US writers, sometimes even in the same sentence when referring to the same person. Black slaves were a very small fraction of the total slave population in the 1600s, only about 10% on average for the century. In the 1700s it averaged about 60% white, 30% black, 10% mixed and other. It wasn’t until the early 1800s that it really started being seen in racial terms with a vast majority being black. Otherwise, why would the founding documents use terms like “free white men” or “unfree Negroes” if they are redundant?

If all you know of slavery is American whites owning African blacks, then you know less than 1% of the history of slavery… speak on the topic accordingly.