Complex sentence: His lack of education ultimately became an issue throughout Jackson's life and even affected the value of his memorabilia in the collectibles market; because Jackson was illiterate, he often had his wife sign his signature.
Split into simpler sentences: His lack of education ultimately became an issue throughout Jackson's life. It even affected the value of his memorabilia in the collectibles market; because Jackson was illiterate, he often had his wife sign his signature.