Approved April 24, 1800, the act of Congress that made provision for the removal of the government of the United States to the new federal city, Washington, D.C., also established the Library of Congress.

A. Approved April 24, 1800, the act of Congress that made provision for the removal of the government of the United States to the new federal city, Washington, D.C., also established
B. The act of Congress, which was approved April 24, 1800, making provision for the removal of the government of the United States to the new federal city, Washington, D.C., also established
C. The act of Congress approved April 24, 1800, which made provision for the removal of the government of the United States to the new federal city, Washington, D.C., and established
D. Approved April 24, 1800, making provision for the removal of the government of the United States to the new federal city, Washington, D.C., the act of Congress also established
E. Approved April 24, 1800, the act of Congress made provision for the removal of the government of the United States to the new federal city, Washington, D.C., also establishing


I chose E, the supposed OA is A.

A = the act of Congress that made ...., also established <--- not an indepednet claushe, WRONG!!

anyone?

that is, indeed, an independent clause. the problem is that it's a very long independent clause - the 'middleman' itself is longer than most actual sentences. that's a doozy.

remember that you should either condense or eliminate these interloping constructions (modifiers, prepositional phrases, and the like) so that you can better understand the structure of the sentence. if you do that here, you get the following:
the act that did X ... also did Y
that's an independent clause.

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the big problem with choice e is that it strips 'the act of congress' of a necessary modifier - so that, instead of saying 'the act of congress that did blah blah blah', it just says 'the act of congress' - as if congress has only ever performed one act in its history. that's an unacceptable (and absurd) change in meaning.

Instructors, a question here.

In the above choice (E), is it correct to say X did Y, also doing Z?

Should it not be : X did Y, doing Z?

Is the use of 'also' correct here, if not redundant?

Great question, Eyunni! Choice (E) in its entirety:

Approved April 24, 1800, the act of Congress made provision for the removal of the government of the United States to the new federal city, Washington, D.C., also establishing the Library of Congress.

The bold text is the non-modifer "core" of the sentence, of the form "X made Y, also establishing Z." You may note that the comma before "also" is required after Washington, D.C., therefore is independent of the question you and the original poster raise about the final clause.

There are two potential problems/fixes to this core.
1) Parallelism: "X made Y and established Z" would be better.
2) Improper modifier form: "X made Y, establishing Z" is grammatically correct, as you suggested.

But I think #2 creates an unintended meaning: The act of Congress made provision (for moving to D.C.), thereby establishing the Library of Congress. It wasn't the move to D.C. that created the Library of Congress. Rather, the act did both of those things.