Radford was attached April 24, 1844, to Warren and visited Society Islands, Sandwich Islands and the western coastline of the Americas.
Commodore Dallas died at Callao, Peru and was replaced by Commodore John Sloat.
 Radford's January 1845 letter to brother-in-law Stephen Kearny predicted California "can never be a very densely populated country" and Oregon "is not a very desirable country" yet "we should and ought by rights to have some possessions on the Pacific".
 He also mentions that "dysentery killed seven of the crew" and that "I was dangerously ill myself".

By May 1845 at Callao, he was again debilitated by dysentery to a degree where ship surgeons recommended he should be removed from the ship "to a more favorable climate".
 However he remained aboard and, through mid-1845, patrolled the California coast where rumor of war with Mexico was rife.

Reaching Honolulu October 4, 1845, orders were received that once Mexico declared war, the squadron should "blockade or occupy such ports as force might permit".
 Warren set return sail on October 16 to Mazatlán to await the onset of war.
Months passed until June 6, 1846, when confirmation arrived from William Maxwell Wood that land war had commenced.
 Warren remained at Mazatlán as the other ships of the squadron captured ports along the California coast, generally with the inhabitants cooperating.
 English warships, also awaiting news of war, reacted too late to offer their protectorate flags to Mexico.

Warren left Mazatlán with dispatches from Washington, D.C. and arrived at Monterey on August 17, 1846, to find Commodore Robert Stockton in charge of the Pacific Squadron.
 Ordered back to resume the blockade of Mazatlán, Warren arrived early morning of September 7 to find the Mexican warship Malek Adhel in the harbor.
 Radford commanded the boarding party which inserted during the siesta hour and securely fastened the hatches while the entire crew was below deck.
 Over the course of the next months, "13 or 14" additional ships were captured by the blockade, eliminating further threat from the Mexican Navy.

Despite the ease of the Conquest of California for the Navy, hostilities continued on land until a flag of truce was delivered by residents of Los Angeles on January 10, 1847.
 General Stephen Kearny paid a visit February 17, 1847, to his brother-in-law at Yerba Buena.
 After nearly four years abroad, Radford was granted leave to depart May 31, 1847, for home overland with Kearny and his troops.
Radford was attached April 24, 1844, to Warren and visited Society Islands, Sandwich Islands and the western coastline of the Americas. Commodore Dallas died at Callao, Peru and was replaced by Commodore John Sloat.  Radford's January 1845 letter to brother-in-law Stephen Kearny predicted California "can never be a very densely populated country" and Oregon "is not a very desirable country" yet "we should and ought by rights to have some possessions on the Pacific".  He also mentions that "dysentery killed seven of the crew" and that "I was dangerously ill myself".
By May 1845 at Callao, he was again debilitated by dysentery to a degree where ship surgeons recommended he should be removed from the ship "to a more favorable climate".  However he remained aboard and, through mid-1845, patrolled the California coast where rumor of war with Mexico was rife.
Reaching Honolulu October 4, 1845, orders were received that once Mexico declared war, the squadron should "blockade or occupy such ports as force might permit".  Warren set return sail on October 16 to Mazatlán to await the onset of war. Months passed until June 6, 1846, when confirmation arrived from William Maxwell Wood that land war had commenced.  Warren remained at Mazatlán as the other ships of the squadron captured ports along the California coast, generally with the inhabitants cooperating.  English warships, also awaiting news of war, reacted too late to offer their protectorate flags to Mexico.
Warren left Mazatlán with dispatches from Washington, D.C. and arrived at Monterey on August 17, 1846, to find Commodore Robert Stockton in charge of the Pacific Squadron.  Ordered back to resume the blockade of Mazatlán, Warren arrived early morning of September 7 to find the Mexican warship Malek Adhel in the harbor.  Radford commanded the boarding party which inserted during the siesta hour and securely fastened the hatches while the entire crew was below deck.  Over the course of the next months, "13 or 14" additional ships were captured by the blockade, eliminating further threat from the Mexican Navy.
Despite the ease of the Conquest of California for the Navy, hostilities continued on land until a flag of truce was delivered by residents of Los Angeles on January 10, 1847.  General Stephen Kearny paid a visit February 17, 1847, to his brother-in-law at Yerba Buena.  After nearly four years abroad, Radford was granted leave to depart May 31, 1847, for home overland with Kearny and his troops.
William Radford