Marriage licenses are issued by the state. In most cases the state has directed the county handle the registration.
Marriage licenses are usually issued at the county level.
Each individual state makes their own laws about marriage licenses. These laws then authorize town, city and/or county clerks in that state to issue marriage licenses to qualified applicants.
No, Congress does not issue marriage licenses. Marriage licenses are typically issued by state or local governments in the United States, as marriage laws fall under state jurisdiction. While Congress can influence marriage laws through legislation, the actual issuance of licenses is managed at the state level.
In the United States, the states have always regulated eligibility and validity of marriage. Only once before, in the issue of interracial marriage, did the federal government overrule states rights in this regard.
Marriage law is within the jurisdiction of the States and, therefore, its enforcement would be a State matter. However, the federal government can sometimes get involved when the state violates federal law. An example of a precedent would be President Eisenhower's sending Federal troops to Little Rock, AR in the 50's to enforce desegregation of the high school there. So if the federal government ever rules in favor of marriage equality, and states refuse to comply, it is a possibility.
WHICH license? Driver's licenses are regulated by the states, not the Federal Government. As are, actually, most other licenses. So it depends more on what state you live in.
Civil Unions were invented as an alternative to marriage for same-sex couples. In the United States, all marriages are entered into according to state laws. The federal government does not issue marriage licenses, register marriages, or issue marriage certificates. Since civil unions are analogous to marriages, the same holds true for them.
In general, a marriage is recognized by the federal government and by U.S. state governments if the marriage was considered legal in the jurisdiction in which it was performed (for example, Canada), unless the marriage is against public policy (i.e., incestuous, polygamous, etc.). One important exception is same-sex marriage, which is currently not recognized by the U.S. federal government and by many state governments. States that do recognize same-sex marriages, however, will also recognize a same-sex marriage performed in Canada.
Licenses can be issued by various levels of government, including federal, state or provincial, and local governments, depending on the type of license and the regulatory framework in place. For example, federal governments often issue licenses for activities like broadcasting or aviation, while state governments might issue driver's licenses and professional licenses, such as for healthcare providers. Local governments typically handle permits and licenses related to zoning, business operations, and building codes. Each jurisdiction has its own authority and criteria for issuing licenses.
Most of the controls over driving licenses in the United States is done at the state level. Each state has a Department of Motor Vehicles or equivalent. In a few states the issuance of licenses is at the county or town level (New Hampshire is an example). The federal government has issued certain guidelines for states to follow but they do not have the full force of law. For example, the federal government has requested that states verify citizenship when issuing licenses, but many states do not do this.
The individual state legislatures enact the laws concerning marriage licenses. These then empower town clerks, city clerks and county clerks to "make" and issue the licenses pursuant to applicable state law.
That's because the state governments control and maintain the public roads and because any power not specifically granted to the federal government in the Constitution belongs to the states.