Dr Freeland skipped the Kentucky Derby, ran last in the Belmont Stakes.
2 years later his owner flicked him off to somebody else, he won only mid tier races beyond the Preakness, some of which were claimers.
The best horses of the early 1930's era in the USA were known as the Big 4. They were Twenty Grand, Jamestown, Equipoise and Mate.
Other top class US horses at this time were Plucky Play and Gallant Sir
Mate also raced successfully internationally winning the Group 2 Challenge Stakes at Newmarket in England and ran 2nd in the Group 1 Coronation Cup.
None of the above horses competed in Mexico.
Phar Lap's Agua Caliente Handicap was only described as the most lucrative race in North America at the time. The field was described as moderate.
Gallant Sir won the Agua Caliente Handicap the year after Phar Lap, breaking Phar Lap's track record in the process, and won again the following year as well.
There were only ever 2 other renditions of the Agua Caliente Handicap beoynd this, 1938 when Sea Biscuit won, and 1958 when it was won by one of America's greatest horses in Round Table.