General Sweeny died at his residence, 126 Franklin street, Astoria, Long Island, April 10, 1892. He was buried in the family plot, Greenwood cemetery, with military honors, six batteries of the First U. S. Artillery furnishing the escort. The following are a few of the many tributes paid the deceased soldier:
Gen. W. T. Sherman: “One of my ‘Old Guard.’”
Gen. J. M. Schofield: “General Sweeny was regarded by all who knew him as an exceedingly brave soldier and an ardent patriot.”
Gen. F. Sigel: “He was an eminent soldier and a patriotic citizen.”
Gen. Robert Nugent: “His gallant and unblemished record in the army is a matter of history.”
Gen. John P. Hawkins: “He was a brave soldier and an honest man.”
Army and Navy Journal: “As gallant, warmhearted and impulsive an officer as ever wore the uniform.”
Archbishop Ryan of Philadelphia: “Many noble qualities distinguished that truly Christian soldier.”
Harper’s Weekly: “A distinguished soldier of three wars, whose conduct at Shiloh won Sherman’s especial praise.”
New York Recorder: “From lieutenant, to brigadier-general, he honored every position held by him during a period of service commencing with the Mexican War.”