United States Navy

==== Frigates and Littoral combat ships ====
{{Main|List of frigates of the United States Navy}}
{{See also|Littoral combat ship}}
[[File:USS Independence LCS-2 at pierce (cropped).jpg|thumb|{{USS|Independence|LCS-2|6}}, a [[littoral combat ship]]]]

Modern U.S. [[frigate]]s mainly perform anti-submarine warfare for carrier and expeditionary strike groups and provide armed escort for supply convoys and merchant shipping. They are designed to protect friendly ships against hostile submarines in low to medium threat environments, using torpedoes and LAMPS helicopters. Independently, frigates are able to conduct counterdrug missions and other maritime interception operations. As in the case of destroyers, frigates are named after U.S. Navy, Marine Corps, and Coast Guard heroes.

In late 2015, the U.S. Navy retired its most recent class of traditional frigates in favor of the littoral combat ship (LCS), relatively small vessels designed for near-shore operations that was expected to assume many of the duties the frigate had with the fleet. The LCS was "envisioned to be a networked, agile, stealthy surface combatant capable of defeating [[Anti-access/area denial|anti-access]] and [[Asymmetric warfare|asymmetric threats]] in the [[Littoral zone|littorals]]",<ref>{{cite web |title=Product Lines at Supship Bath |url=http://www.navsea.navy.mil/supship/Bath/Products.aspx |url-status=dead |archive-url=https://web.archive.org/web/20120301113457/http://www.navsea.navy.mil/supship/Bath/Products.aspx |archive-date=1 March 2012 |access-date=8 May 2012 |publisher=Navsea.navy.mil}}</ref> although their ability to perform these missions in practice has been called into question.<ref>{{Cite news |date=2023-02-04 |title=The Pentagon Saw a Warship Boondoggle. Congress Saw Jobs. |url=https://www.nytimes.com/2023/02/04/us/politics/littoral-combat-ships-lobbying.html |access-date=2023-03-21 |work=The New York Times |language=en-US}}</ref> The Navy has announced it plans to reduce procurement of the LCS and retire early examples of the type.

In the future, the Navy plans to purchase up to 20 of the {{sclass|Constellation|frigate|1}}, based on the [[FREMM multipurpose frigate]], already in service with European navies.

The U.S. Navy currently has 23 littoral combat ships, eight {{sclass|Freedom|littoral combat ship|0}} and 15 {{sclass|Independence|littoral combat ship|0}} ships.

[[File:USS Constitution fires a 17-gun salute.jpg|thumb|[[USS Constitution|USS ''Constitution'']], firing a 17-gun salute in 2014]]
A special case is the {{USS|Constitution}}, commissioned in 1797 as one of the original six frigates of the United States Navy and which remains in commission at the Charlestown Navy Yard in Boston. She occasionally sails for commemorative events such as [[Independence Day (United States)|Independence Day]].