Alaska.[680] In 1841 it was reckoned that one third of the entire population from northern British Columbia to southern Alaska were "slaves of the most helpless and abject description." "The great supply was obtained by trade with the southern Indians, in which the Tsimshian acted as middlemen. They were kidnapped or captured by the southern Indians from their own adjacent tribes and sold to the Tsimshian, who traded them to the northern Thlinkit and interior Tinne tribes for furs." "Slaves did all the drudgery, fished for their owner, strengthened his force in war, were not allowed to hold property or to marry, and when old and worthless were killed. The master's power was unlimited." The slave must commit any crime at the command of the master. The slaves were set free at some ceremonies, but they were put to death at the funerals of chiefs, or as foundation sacrifices, or in reparation for insults or wrongs. The northern Indians were more warlike and would not make good slaves. The Oregon flatheads were docile and industrious.[681] The Chinooks became the wealthiest tribe in the region by acting as middlemen to sell war captives taken inland as far from home as possible.[682] Amongst the Thlinkits slaves are forbidden to wear the labret, and sex intercourse with a slave woman disgraces a free man.[683] "Amongst the early Central Americans the slave who achieved any feat of valor in war received his liberty and was adopted by the Capulli, or clan."[684] In Mexico there were slaves of three classes,--criminals, war captives, and persons who had voluntarily sold themselves or had been sold by their parents. The captor generally sacrificed a prisoner, but might hold him as a slave. Those who sold themselves did so to get a fund for gambling. There was a public slave mart at Azcapuzalco. The system is described as kind, but slaves might lose their lives through the act of the master at feasts or funerals.[685] "Actual slavery of the Indians in Mexico continued as late as the middle of the seventeenth century."[686] It is evident that slavery existed all over North and Central America, but was more developed on the Pacific coast than in the Mississippi valley. The meat eaters of the buffalo region had less opportunity to use the institution.[687]