In 1850, Father Sorin made his first attempt to secure a postal station for Notre Dame. The effort failed since it was “unnecessary” for Notre Dame to have its own separate post office from the neighboring town of South Bend, IN.
Per bioguide.congress.gov, with the support of Senator Henry Clay and Congressman Fitzgerald of Niles, MI, new requests were approved on January 6, 1851. Father Sorin became postmaster, serving until his death in 1893.
After the establishment of Notre Dame’s post office, the US Postal Service's four horse mail coaches stopped at the University three times a week enroute from Logansport, IN to Niles. As Father Sorin wrote, "The regular passage of the mail coach under the college windows makes the college better known, and causes the public highways leading to it to be carefully maintained." ~excerpt from Notre Dame: One Hundred Years, by Arthur J. Hope, C.S.C.