Michael Mengine was employed by the United States Postal Service (USPS) as a letter carrier.

Following hip surgery, he was no longer able to perform the duties of a letter carrier, which required prolonged walking and substantial lifting. Mengine went on sick leave, but after exhausting his leave, he requested assignment to light duty work. The USPS assigned him to temporary light duty work for a month, but after the expiration of that temporary position, the Postal Service informed him that there were no permanent light duty positions available.

Mengine asked the USPS to create a permanent light duty position for him, but that request was refused and Mengine ultimately took disability retirement.

He then filed suit under the ADA, alleging that the USPS refused to offer him a reasonable accommodation.

Has the USPS violated the ADA? Explain. See Mengine v. Runyon [114 F.3d 415 (3d Cir. 1997)].