How was this section of the 14th amendment significant to reconstruction?

Section 2. Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed., all slaves are now counted as a whole person for purposes of representation and taxation, whereas they were counted as three-fifths a person while slavery was intact. This vastly increased the Congressional representation of the southern states, threatening the northern stranglehold of power during the Civil War.

What is unclear about this?

"...vastly increased the Congressional representation of the southern states, threatening the northern stranglehold of power..."

"representation" = number of congressmen in the House of Representatives

To understand why this section of the 14th Amendment was significant to Reconstruction, we need to provide some historical context. The Reconstruction period followed the American Civil War (1861-1865) when the Union (the northern states) defeated the Confederacy (the southern states). Reconstruction aimed to rebuild and reunite the United States, addressing issues such as slavery, the rights of formerly enslaved individuals, and the reintegration of Confederate states into the Union.

Section 2 of the 14th Amendment addressed the issue of congressional representation. Prior to the Civil War, enslaved individuals, who were primarily located in the southern states, were counted as three-fifths of a person for the purpose of determining congressional representation and taxation. This 3/5ths compromise in the Constitution was a result of the political tensions between northern and southern states, as the former wanted enslaved individuals to count for a smaller number of representatives.

With the abolition of slavery after the Civil War, the 14th Amendment's Section 2 changed the previous practice significantly. It stated that all persons, including former slaves, would now be counted as a whole person for purposes of representation and taxation. This shift had a significant impact during Reconstruction because it drastically increased the congressional representation of the southern states.

By counting formerly enslaved individuals fully, the southern states gained more seats in the U.S. House of Representatives. This threatened the northern states' stranglehold on power, which was established during the Civil War. The northern states feared that this influx of southern representatives could potentially impact national legislation or even obstruct the progress made in the rights of formerly enslaved individuals.

Overall, Section 2 of the 14th Amendment was significant to Reconstruction as it aimed to address the issue of how to count enslaved individuals for congressional representation and taxation, and in doing so, it significantly impacted the balance of power between northern and southern states.