For the purpose of preserving more effectively for the public benefit the historic properties within Colonial National Historical Park, Virginia, the Secretary of the Interior is authorized to consummate desirable land exchanges, as hereafter prescribed, and thereby to reduce and adjust the boundaries of the park. Any lands eliminated from the park hereunder shall not subsequently be added to the park except by Act of Congress.

In furtherance of these purposes, the Secretary is authorized on behalf of the United States to accept from grantors title to non-Federal land and interests in land, together with the improvements thereon, situated within the authorized park boundaries, and in exchange therefor, to convey by deed on behalf of the United States to the aforesaid grantors land or interests therein, together with the improvements thereon, situated within Colonial National Historical Park that may be used advantageously for exchange purposes. The aforesaid exchanges are authorized to be made without additional compensation by either party to the exchange when the properties to be exchanged are of approximately equal value. When, however, the properties are not of approximately equal value, as may be determined by the Secretary, an additional payment of funds shall be required by the Secretary or by the grantor of non-Federal properties, as the case may be, in order to make an equal exchange. The Secretary is authorized to use any land acquisition funds relating to the National Park System for such purposes. The Secretary may consummate land exchanges herein authorized upon such terms, conditions, and procedures as he may find to be necessary or desirable in carrying out the purposes of this section and section 81n of this title; and in evaluating non-Federal properties to be acquired hereunder, he is authorized to make such allowance as he may find to be equitable for the value of any residential properties that may be situated upon land to be acquired pursuant to this section and section 81n of this title. If expedient and in the public interest to do so, he may assist in the removal of structures from property to be acquired hereunder through the exchange procedure, and he may cooperate with public or private agencies and persons in the securing of housing for the aforesaid grantors who may require new housing accommodations or facilities as a result of the land exchanges herein authorized.