Origin of the term "Christmas tree bill"

I’ve researched the origin of the “Christmas tree bill” (a bill with lots of added presents for many legislators). I give credit to Michigan Republican Senator Arthur H. Vandenberg (1884-1951) based on these on these 1930 statements. Wikipedia has 1956:

13 April 1930, New York (NY) Times, “Assails Project for Erie Canal: Senator Vandenberg Tells Hoover It Is Plot to Kill St. Lawrence Seaway,” pg. 23:
“It is simply impossible for those of us who come from the Great Lakes sector to surrender the St. Lawrence seaway to any such obnoxious, indefensible Christmas-tree ideal. It remains to be seen whether this tentative rivers and harbors bill is sufficiently well greased so that it can slide through regardless of opposition.

But at any rate the opposition will not surrender without a fight which will be reminiscent of those of other days when pork barrel legislation of this type was effectually discouraged.”

29 April 1930, New York (NY) Times, pg. 25:
Senator Asserts Hoover Would
Not Sign House Rivers and
Harbors Bill
WASHINGTON, April 28.—Senator Vandenberg of Michigan today declared that the river and harbors bill as passed last week by the House would not be approved by president Hoover and that many of its projects must be eliminated to win his signature. He especially attacked the Erie and Illinois canal projects.

“I do not believe,” said Senator Vandenberg, “that the Senate will approve the fat rivers and harbors bill in any such form as it was jammed through the House at a single high-pressure sitting. There are too many suspicious presents on the Christmas tree. The bill must be debunked.”

Google Books
14 May 1930, Owosso (MI) Argus-Press, pg. 2, col. 1:
Senator Vandenberg Says
That Measure is a Real
“Christmas Tree”
(Associated Press Staff Writer)
Washington, May 14.—(AP)—Threats of a filibuster in the Senate against the $110,535,027 House rivers and harbors bill were encountered today with warnings that the House would keep Congress in session this summer until the controversial measure is enacted.

Reasonable Deduction
Representative Tilson of Connecticut, the Republican leader in the House, conceded that the report of a move to keep Congress going until the bill is passed “is a very reasonable deduction.”

Senator Vandenberg, Republican, Michigan, who is fighting a provision for the federal government to take over the Erie Canal in New York State, reiterated that there would be “some long talking in the Senate” before “this Christmas tree bill” got through.

1 June 1930, Cleveland (OH) Plain Dealer, pg. 13, col. 1:
“Pork Barrel’ Features of
Measure Assailed; Good
Points Win Votes.
Senator Vandenberg describes it as a “Christmas tree” bill, with everybody rushing to get a “present,” before Congress adjourns.

2 June 1930 Cleveland (OH) Plain Dealer, editorial, pg. 12, col. 2:
He calls the rivers and harbors measure a “Christmas tree bill.” There’s a present for everybody on it and that is why so few of the Senators are moved to see its evils.

The indictment that Senator Vandenberg draws against the bill is convincing.

FYI, Wikipedia has this on Vandenberg:

When the new Congress convened in 1935, there were only twenty-five Republican senators, and Vandenberg was one of the most effective opponents of the second New Deal. He voted against most Roosevelt-sponsored measures, notable exceptions being the Banking Act of 1935 and the Social Security Act. He pursued a policy of what he called fiscal responsibility, a balanced budget, states’ rights, and reduced taxation. He felt that Roosevelt had usurped the powers of Congress, and he spoke of the dictatorship of Franklin Roosevelt. But at the 1936 Republican National Convention, Vandenberg refused to permit the party to nominate him for Vice President; he sensed the coming debacle and did not want to suffer a humiliating defeat.

As part of the conservative coalition of Republicans and Democrats in the Senate, Vandenberg helped defeat Roosevelt’s attempt to pack the Supreme Court. Thereafter, Vandenberg worked closely with this group. He helped defeat such pork-barrel legislation as the Passamaquoddy Bay and Florida Canal projects, voted against the National Labor Relations Act, various New Deal tax measures, and the Hours and Wages Act.