Genesis 9:18-29 -- Noah's Nakedness

18 Noah’s sons who came out of the ark were Shem, Ham, and Japheth. Ham was the father of Canaan. 19 These three were Noah’s sons, and from them the whole earth was populated.
20 Noah, a man of the soil, was the first to plant a vineyard. 21 He drank some of the wine, became drunk, and uncovered himself inside his tent. 22 Ham, the father of Canaan, saw his father naked and told his two brothers outside. 23 Then Shem and Japheth took a cloak and placed it over both their shoulders, and walking backward, they covered their father’s nakedness. Their faces were turned away, and they did not see their father naked.
24 When Noah awoke from his drinking and learned what his youngest son had done to him,25 he said:
Canaan will be cursed.
He will be the lowest of slaves to his brothers.
26 He also said:
Praise the Lord, the God of Shem;
Canaan will be his slave.
27 God will extend Japheth;
he will dwell in the tents of Shem;
Canaan will be his slave.
28 Now Noah lived 350 years after the flood. 29 So Noah’s life lasted 950 years; then he died.

Noah pronounced a punishment on Canaan.  Ham was the one who looked upon his father's nakedness, but did nothing about it, but Canaan was punished.  He and his offspring were to be the slaves of Ham's brothers, Shem and Japheth.  Why was Canaan punished for Ham's wrong?

Exodus 34:7 But He will not leave the guilty unpunished, bringing the consequences of the fathers’ wrongdoing on the children and grandchildren to the third and fourth generation.

The Bible states that the children and grandchildren will suffer for the sins of their fathers.  If you do something wrong, others are impacted as well.  If you do wrong and must be punished by going to jail, then your children will suffer for not having you there.  Now, that is just a simple example, but in Bible, the wrong of one man could impact all his offspring and descendants.

Also keep in mind that Canaan is the ancestor who gave rise to the Canaanites.  Abram was promised the Canaanite land for his future descendants.