Answer:
To him, transportation and communication have "Space is comparatively annihilated. Thoughts expressed on one side of the Atlantic are distinctly heard on the other. " (“Frederick Douglass' Speech For July 4 ... - Countercurrents”)
This shows a vision of the future, even if it is not all positive. The abolition of space has enabled "real-time" reporting of events, resulting in significant global change. In closing, he quotes William Lloyd Garrison, implying the great abolitionist's new global reach across the ocean.
I doubt Douglass could have predicted today's technology or its uses. Communication has enabled much greater organizing and mobilization. Although it has aided the spread of hateful ideas and lies, I believe Douglass would have admired our ability to capture and transmit video of events. This power fuels modern anti-human trafficking, prison, and police movements.