What does the name of U.S. President Eisenhower mean in German?

"Eisen" is German for "iron". For the second part, one must look at the German word "Hauer", pronounced like the English "Hower". It has a variety of translations to English, one of which is "hewer". A word that I (non-native speaker of English) have never come across.

a person who cuts wood, stone, or other materials

https://translate.google.com/#en/de/hewer

Add them together, and "Eisenhower" would be a metalworker of some kind.

Having done that analysis, I see that Wikipedia agrees:

The Eisenhauer (German for "iron hewer/miner") family migrated from Karlsbrunn in the Saarland, to North America, first settling in York, Pennsylvania, in 1741, and in the 1880s moving to Kansas.

https://en.wikipedia.org/wiki/Dwight_D._Eisenhower#Early_life_and_education