Just a side note on what Frozen posted.
“To double plow, harrow and seed an acre (using a single furrow horse-drawn plow) might take a day or might take two. To do it by hand with hoes or mattocks would take a lot longer”
If you are using a draft animal in previously improved soil. (it has been plowed or turned over before) you turn over about a 14″ furrow of soil as fast as the animal can walk. If you are doing this by hand a 6-8 inch row maybe 40′-75′ in an hour (depending on your fitness & soil type).
From my own personal experience I would recommend using a shovel (sharp spade) for turning soil and save the use of hoes and mattocks for lighter work like breaking clods & cultivating. When using a shovel you use your weight to drive the tool into the ground. Conserve your movement and don’t move the soil far, just turn it over. Swinging a mattock requires gross body movements requiring a lot of energy.
If you are preparing a garden in very hard ground using a mattock might be your best option, woe is me.