Final answer:
Immigrants came to the Republic of Texas and the Republic of California primarily for the availability of cheap land. Major differences between American settlers and tejanos in Texas included slavery ownership and religious distinctness. Chinese immigration was prominently driven by the California Gold Rush.
Step-by-step explanation:
Most immigrants to both the Republic of Texas (RoT) and the Republic of California (SoT) came mainly because of the availability of cheap land. The government of Mexico, aiming to attract immigrants to Texas, offered land at a low price, much cheaper than comparable land costs in the United States at the time. Moreover, immigrants were drawn by the prospect of purchasing large tracts of land, with allowances made based on family size and slaves brought into the province.
American settlers migrated to the Mexican province of Texas but maintained their cultural and religious distinctiveness from the tejanos. The primary differences were that many American settlers were slave owners and they remained religiously distinct, being predominantly Protestant and unaccustomed to the Roman Catholic practices of the tejanos.
Additionally, for Chinese immigrants, the major lure was the discovery of gold in California, which led many to migrate in search of wealth and economic opportunity.