President Lincoln delayed issuing an Emancipation Proclamation because of his concern that it would:

cause the border/southern states to secede from the Union.

Explanation:

basically the states that wanted to keep slavery, the states whose economy depended on slavery,

- three-quarters or two-thirds..

- "the constitution provides that an amendment may be proposed either by the congress with a two-thirds majority vote in both the house of representatives and the senate or by a constitutional convention called for by two-thirds of the state legislatures."

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