Historically, alimony arose as a result of the indissoluble nature of marriage. Because divorce was rare, husband and wife remained married after their physical separation and the husband's obligation to support his wife continued. With the growing view that men and women should be treated equally the law recognized that both husbands and wives owed each other a similar duty of support. Accordingly, courts now may order either the husband or wife to pay alimony (Especially in cases where the wife was the primary breadwinner.), though in practice it is more often the husband.
Alimony is treated very differently to child support in the United States with respect to taxation. Alimony is treated as income to the receiving spouse, and deducted from the income of the paying spouse. Child support is not a payment that affects US taxes as it is viewed as a payment that a parent is making for the support of their own offspring.
If a party fails to pay alimony, there are not generally any special legal options available to the party that is owed money. In many jurisdictions, people whose child support obligations go into arrears can have licenses seized, in a few states they can even be imprisoned. Someone trying to recover back alimony can sometimes only use the collection procedures that are available to all other creditors (for example, (s)he could report the back alimony to a collection agency). In some states, if someone is unable to pay all of their alimony, they will be found in contempt of court and placed in jail.