property: (1) something, as land and assets, legally possessed, (2) a piece of real estate, (3) something tangible or intangible to which its owner has legal title, (4) the right of ownership; title.

Note: When speaking of territorial cession(s) between states, land area is certainly considered to be "property."

In other words, Louisiana was originally the property of France, but was ceded to the USA in 1803. Florida was originally the property of Spain, but was ceded to the USA in 1821.

Other examples are quite numerous, including

Name of Cession	Date	Originally the property of
California	1848	Mexico
Gadsden Purchase	1853	Mexico
Alaska	1867	Russia
Guam	1899	Spain
Puerto Rico	1899	Spain
Virgin Islands	1917	Denmark

                etc.