Which is the best example of a "robber baron" using his wealth in a "philanthropic" manner?

For me, the best example of a Robber Baron using their money for charity is Andrew Carnegie.

Carnegie became famous for building a total of 2,509  libraries between 1883 and 1929.

B) Cornelius Vanderbilt and the $1 million endowment he gave to Vanderbilt University.

"Robber barons" were powerful businessmen of the 19th-century United States who made their fortunes through dubious practices. Some of these morally questionable strategies are monopolies, the formation of trusts, exploitation of workers, etc. Cornelius Vanderbilt is an example of this type of industrialist. Moreover, a donation to Vanderbilt University is likely to be seen by most people as a "philanthropic" or charitable act.

the answer to your question is,

old stone age.

-mabel < 3