He was the poet of the squalid and felt that terror, pity, and beauty lurked under the American dream. A few words have been changed or omitted, but by no strench of the imagination is the student writer using his own language. Nothing was genteel about Dreiser as a man or as a novelist. He was the poet of the squalid and felt that terror, pity, and beauty lurked under the American dream. Not quite plagiarism, but incorrect and inaccurate.
Quotation marks indicate exact repetition of what was originally written.
The student writer, however, has changed some of the original and is not entitled to use quotation marks. Certainly there was nothing genteel about Drciser, either as man or novelist. He was the supreme poet of the squalid, a man who felt the terror, the pity, and the beauty underlying the American dream. The quotation marks acknowledge the words of the original writer. The footnote is also needed, of course, to give the reader specific information about the source of the quote.