In 1954, he sponsored the bill creating the Saint Lawrence Seaway, which allowed large ocean-going vessels access to the Great Lakes.

In 1947, Dondero tried to block the trial of IG Farben executives for war crimes at Nuremberg by withholding funding for the prosecution team before indictments could be handed down.

[2] On July 9, 1947, Dondero included Rosenberg when he publicly questioned the "fitness" of US Secretary of War Robert P. Patterson for failing to ferret out communist infiltrators in his department.

His cause for concern arose from what Dondero called Patterson's lack of ability to "fathom the wiles of the international Communist conspiracy" and to counteract them with "competent personnel."

"[7] When Genauer pointed out the resemblance between his views and those of the Stalinist communists that he despised, Dondero was so enraged that he arranged to have her fired from her job at the New York Herald Tribune.