 <translate> The relevant information is: The Post Office Department was created in 1792 from Franklin's operation, elevated to a cabinet-level department in 1872, and transformed in 1971 into the U.S. Postal Service as an independent agency. The answer is 1971. <yor> Ìsọfúnni tó bá a mu ni pé: Ẹ̀ka Ọ́fíìsì Ìfìwéránṣẹ́ ni a dá ní 1792 láti inú iṣẹ́ Franklin, tí a gbé ga sí ẹ̀ka tí ó wà ní ìpele ilé-ìgbìmọ̀ ní 1872, tí a sì yí padà ní 1971 sí Ẹ̀ka Ìfìwéránṣẹ́ ti Orílẹ̀-èdè Amẹ́ríkà gẹ́gẹ́ bí àjọ tí ó dá dúró. Ọdún 1971 ni ìdáhùn náà. 