Complex sentence: The "Mont Sainte-Victoire and the Viaduct of the Arc River Valley" was a bequest of "Mr. H. O. Havemeyer" and "Louisine Waldron Elder Havemeyer", which was donated to the museum in 1929, after Louisine died earlier that year.
Split into simpler sentences: The "Mont Sainte-Victoire and the Viaduct of the Arc River Valley" was a bequest of "Mr. Henry Osborne Havemeyer" and "Louisine Waldron Elder Havemeyer". The work was later donated to the museum in 1929, after Louisine died earlier that year.