<prompt> Translate the following text to EnglishCasellas alianza kazi yake katika kampuni ya sheria ya Philadelphia Montgomery, McCracken, Walker na Rhoads, ambapo alifanya kazi kwa miaka kumi na sita.  <response>: Mr. Casellas began his career at the Philadelphia law firm Montgomery, McCracken, Walker and Rhoads, where he worked for sixteen years. 