It is necessary not only to cite all sources but also to make clear which information comes from you and which comes from a source. Signal phrases help to introduce material borrowed from a reference. A signal phrase is a phrase, clause, or even sentence which leads into a quotation or statistic. These generally include the speaker/author’s name and some justification for using him or her as an expert in this context; it may also help establish the context for the quotation.
Don’t always quote: (sometimes it makes more sense to paraphrase BUT you still have to cite it.
The quote from Wendell Phillips:
“Treason should have been punished by confiscating its landed property.... Land should have been divided among the negroes, forty acres to each family, and tools--poor pay for the unpaid toil of six generations on that very soil. Mere emancipation without any compensation to the victim was pitiful atonement for ages of wrong.”
“The South owes to negro labor and to legislation under negro rule all the prosperity she now enjoys--prosperity secured in spite of white ignorance and hate.”
Instead, you might write in your essay:
We as a nation owe these people something for the generations they and their ancestors were enslaved. Many, including Wendell Phillips, the famed abolitionist, feel that every slave family should have received land and tools upon receiving their freedom. We did NOT do that, but now we have the chance to correct that shortsightedness and achieve true justice. And Phillips, like many others such as Thaddeus Stevens, understands that land alone will not be enough; a farmer needs something to start with--tools, a draft animal like a mule, or cash--things that will allow him to farm this land.*
You’ve used the idea and cited it by referring to him and including a footnote, and you’ve explained it.
The footnote goes at the end of the sentence/idea/quotation. (I couldn't include it here, so used the * to indicate the fn.)