Edwin R. Blackwell was an accomplished civil engineer living in Black Rock New York, near the Niagara Falls in the mid to late 19th century. Blackwell worked with various railroad companies and contractors as a surveyor and engineer and was highly regarding for this work in the Buffalo, New York area. Blackwell is best known for his 1841 work, in conjunction with Z. Allen, in the surveying of the Falls and calculation of the power of the Falls. Based on detailed measurements and various soundings Blackwell determined that the horse-power generated by the falls was 4,533,334. Click here for a list of rare maps from Edwin R. Blackwell .