Loesser purchased his Villa Torri Gattaia, nestled in the Florentine hills behind San Miniato al Monte, around 1908 and started on renovations.

In Florence, Loeser devoted himself to his studies and the collecting of works of art, and furniture that was flooding the market at the turn of the century.

it contained over two hundred and fifty Old Master prints and drawings, numerous period furnishings, paintings, sculptures and works of applied art.

Loeser died at the Ritz-Carlton Hotel during a visit to New York on March 15, 1928, and was buried at Cimitero Evangelico agli Allori in Florence.

The Bequest still adorns the rooms of the Quartiere del Mezzanino of Palazzo Vecchio, laid out in line with aesthetic canons similar to those that characterized the interiors of the aristocratic mansions of Renaissance Florence, and which the collectors of Loeser's time tended to reproduce in their private residences.