Genesis 9:26-29; 10:1-32

The significance of the number 40 in scripture is trial, tribulations, and testings. It is mentioned 146 times in the bible. Examples: Israel is 40 years in the wilderness; Moses was 40 years in Egypt, then 40 years in Median as a servant, 40 years on mountain, Jonas preached for 40 days in Minima, Jesus was tempted 40 days in the wilderness, etc.
Ham did something very offensive to Noah when Noah was drunk and naked. The other brothers took care of Noah in a respectful manner.

Chapter 9 continued:
25 And he said, Cursed be Canaan; a servant of servants shall he be unto his brethren. Canaan was cursed, not Ham.
26 And he said, Blessed be the LORD God of Shem; and Canaan shall be his servant. All Canaan's descendants will be servants.
27 God shall enlarge Japheth, and he shall dwell in the tents of Shem; and Canaan shall be his servant. Again, the descendants of Ham are going to be servants to the other brother's descendants. Shem occupies the land from the Mediterranean Sea to the Indian Ocean. Ham's descendants occupy Africa, Canaan, and Palestine. Japheth's descendants occupy the coastlands of the Mediterranean Sea, Europe, and Asia Minor. These Caucasians came from Japheth. All the nations and races came from these three sons of Noah. The Canaan descendents were very corrupt and sinful. This curse was from God, passed on by Noah to his sons, which filters down to the rest of humanity. The time frame here is 4500 B.C.
28 ¶ And Noah lived after the flood three hundred and fifty years. To be such a great man of God and do all the things he did and commune with God on a one-on-one basis, the rest of Noah's life is summed up in one sentence.