G.H. Walker apparently even lived and worked in Berlin, establishing Harriman's German banking operations during the period the Nazi Party was first emerging, and then sharing these duties with Prescott after the Nazis took power as the bank's business in the U.S. grew during the 1930s. Along with the Rockefeller-owned Republic Bank, The Union Banking Corp. was the Nazi regime's largest investment vehicle in the United States.
http://www.romm.org/prescott.html Were Bush's great-grandfather and grandfather Nazis?
By David E Romm
with apologies to Cecil Adams
While there are no recorded incidents of them goose stepping or giving the "Heil Hitler" salute, the short answer to the question is yes. Both Bush's grandfather's palled around with sympathizers to the Nazi cause, with George Herbert Walker the worse of the two and grandfather Prescott Bush even worse as he dealt with Nazi Germany before and during WWII.
SNIP
George Herbert Walker married off his daughter to Prescott Bush. It was a good arrangement for both: Prescott married into money and financial connections; the Walkers rose in society and power. A standard trade-off. George Herbert Walker isn't listed as a member of the Skull and Bones Society at Yale, but future son-in-law Prescott is, and the son and grandson named after him are, as are the Bush's who were his grandson and great-grandson. Aside: The Skull and Bones Society itself has been the subject of much speculation especially about the Bushes, and the real story is as interesting, but an entirely different column.
In 1919, Missouri deal-maker Bert Walker became the president and CEO of the W.A. Harriman and co. bank, which became one of the largest companies in the world. In 1922, the Harriman company set up a branch in Berlin under the residency of George H. Walker. In 1924, the Harriman company spun off the Union Banking Corporation , also run by Bert. The UBC was established to send American capital to Germany to finance the reorganization of its industry under the Nazis. Their leading German partner was the notorious Nazi industrialist Fritz Thyssen, who wrote a book admitting much of this called "I Paid Hitler." An article called Nazis In The Attic states boldly, "Walker was one of Hitler's most powerful financial supporters in the United States." and gives other details.