How can one deal with an overbearing mother-in-law who has caused tension in her relationship with her husband, especially after the mother-in-law attempted to control their lives even in America, and her husband refused her request to reduce his mother's visits or to move his mother's work outside the home?

You are not at fault for asking to space out visits from your mother-in-law. Your husband is obligated to balance showing kindness to his mother with treating you well, without neglecting your rights. He must also provide you with a separate home if he wishes to grant his mother free access to his house. Your patience and kindness towards your husband and his mother are righteous deeds, and the kindness shown by each spouse to the other's family strengthens good companionship.