In the late 1800s, what factor most contributed to the successful implementation of the practices of vertical and horizontal integration?

Lack of government regulation of business practices.

Horizontal integration is the practice of buying smaller businesses creating competition so a company can have a monopoly over the sale of an item. Vertical integration is the practice of buying companies that supply the process of of a manufactured item from raw materials to transportation.

Corporate tycoons of the Gilded Age were able to use these economic practices because there were no laws or regulations to prevent them from doing so. John Rockefeller was an expert at horizontal integration. He bought oil industries out so he could be the sole provider of oil in America. Carnegie was an expert in vertical integration. He bought iron mines, creating steel mills, and bought rail lines to transport his goods. These practices made tycoons wildly wealthy which allowed them to continue buying and investing more to become more wealthy and powerful.

the catholic church withhold people's access to the bible during the middle ages.

people could go to church and listen to the teachings, but it was absolutely forbidden to own and/or read the books of both the old and new testaments. it was also prohibited to translate the books (which where originally in biblical hebrew) to any other language.

this was done so the church could remain in control of what their teachings were and to enhance their importance and power, while also being able to judge people's actions through information that was unavailable for the general public.

the exodus of these people from constantinople contributed to the revival of greek and roman studies, which led to the development of the renaissance in humanism and science. byzantine emigrants also brought to western europe the better preserved and accumulated knowledge of their own greek civilization