After this, things went perfectly well, and Mary accepted his proposal to marry him.

proposal 是名词，来自动词 propose（提议、建议），加上名词后缀 -al 构成，表示"提议、建议"的具体内容。 在婚姻语境中，proposal 特指向某人提出结婚的请求，即"求婚"。