What finally convinced the federal government to intervene in the pullman strike in 1894?

The strike disrupted mail delivery.

Explanation:

The Pullman Strike was a railroad strike and boycott that took place in the Midwest in May, June and July, 1894. This strike pitted the American Railway Union (ARU) against the Pullman Company and the federal government. The strike was initiated due to a recent reduction in wages. 30 workers were murdered, and the strike was eventually ended with the use of an injunction. It is now considered a turning point for US labor law.

they are best described as reliable search engines.

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)