Did Grover Cleveland Alexander's father wear a kilt?

Over the weekend Peter Nash, of the Hauls of Shame website, tweeted the following picture:

1916 Grover Cleveland Alexander Handwritten Signed Letter

It came from a recent Heritage Auction sale.

My transcription is:

     Sat Sept 16 16
My Dear Friend
     In reply to  your letter in regard to my nationality I will say I am of Scotch Irish parents.  My Father is a full blooded Scotchman and my Mother is Irish.
     Respectfully
           G C Alexander

"My Father is a full blooded Scotchman and my Mother is Irish."  I like bold statements.  They stand strong and we have to accept them as truth.  We do, don't we?  Well, no, not really.

I figured that Grover's declaration could be verified or disproved.  To ancestry.com I went.

This 1900 US Census page shows that Grover's father, William Alexander was born in Iowa.  Grover's mother, Martha, was born in Wisconsin.  His paternal grandparents were born in Scotland and Ohio.  His maternal grandparents were both born in Ireland.

Source Citation: Year: 1900; Census Place: Fairdale, Howard, Nebraska; Roll: 930; Page: 9B; Enumeration District: 0125; FHL microfilm: 1240930

Source Information: Ancestry.com. 1900 United States Federal Census [database on-line].
Provo, UT, USA: Ancestry.com Operations Inc, 2004.

Moving chronologically through the records, I should find the 1910 US Census.  But I don't.  Or at least I haven't yet.  I found where he isn't.  His parents, William and Maggie J. Alexander, were enumerated in St. Paul, Howard County, Nebraska that year.  He wasn't in with the family.  I don't know where he was when the census takers came calling.

So on to the next item.  It is his World War I draft registration card.  This doesn't talk about his parents' heritage, but it is interesting.

Source Citation: Registration State: Nebraska; Registration County: Howard; Roll: 1711698

Description: Draft Card : A

Source Information: Ancestry.com. U.S., World War I Draft Registration Cards, 1917-1918 [database on-line].
Provo, UT, USA: Ancestry.com Operations Inc, 2005.

Original data: United States, Selective Service System.World War I Selective Service System Draft Registration 

I found Grover in Chicago in 1920.  On the next page is his wife, Amy.  According to this Grover's father was born in Iowa.  What's a few different states between friends?

Source Citation: Year: 1920; Census Place: Chicago Ward 25, Cook (Chicago), Illinois; Roll:T625_342; Page: 3B; Enumeration District: 1477; Image: 1024

Source Information: Ancestry.com. 1920 United States Federal Census[database on-line].
Provo, UT, USA: Ancestry.com Operations Inc, 2010. Images reproduced by FamilySearch.

Original data: Fourteenth Census of the United States, 1920. (NARA microfilm publication T625, 2076 rolls). Records of the Bureau of the Census, Record Group 29. National Archives, Washington, D.C. For details on the contents of the film numbers, visit the following NARA web page: NARA.
Note: Enumeration Districts 819-839 are on roll 323 (Chicago City).

Like the 1910 census I couldn't track down the 1930 census listing Grover.

In 1940 Grover and Mrs. Alexander are in New York.  This census didn't ask where the parents were born.

Source Citation: Year: 1940; Census Place: New York, New York, New York;
Roll: T627_2644;Page: 85A; Enumeration District: 31-844

Source Information: Ancestry.com. 1940 United States Federal Census [database on-line].
Provo, UT, USA: Ancestry.com Operations, Inc., 2012.

Original data: United States of America, Bureau of the Census. Sixteenth Census of the United States, 1940. Washington, D.C.: National Archives and Records Administration, 1940. T627, 4,643 rolls.

Since Grover did serve in the military we have his application for headstone or marker.

Source Information: Ancestry.com. U.S., Headstone Applications for Military Veterans, 1925-1963[database on-line].
Provo, UT, USA: Ancestry.com Operations, Inc., 2012.

Original data: Applications for Headstones for U.S. Military Veterans, 1925-1941. Microfilm publication M1916, 134 rolls. ARC ID: 596118. Records of the Office of the Quartermaster General, Record Group 92. National Archives at Washington, D.C.Applications for Headstones, compiled 01/01/1925 - 06/30/1970, documenting the period ca. 1776 - 1970 ARC: 596118. Records of the Office of the Quartermaster General, 1774–1985, Record Group 92.
National Archives and Records Administration, Washington, D.C.

image by Arthur Koykka
from FindAGrave.com

Grover ended up in Elmwood Cemetery in St. Paul, Nebraska.

So, based on the records from Ancestry.com I'd have to say that I don't know if Grover's dad wore a kilt, but it does seem that his father wasn't born in Scotland and his mother wasn't born in Ireland.  It is too late for me to try to do the ancestral math as to what percentage of what nationality he actually was.