World HIstory Kurtz-Nicholl By twochainz Jan 30, 1840 A number of independant city-states developed. 3000 BC Jan 30, 1840 INvention of the wheel 3000 BC Period: Jan 30, 1840 to Jan 30, 1850 2200 to 2700 BC Old Kingdom Jan 30, 1845 Uruk reaches population of 50000 2700 BC Jan 30, 1845 Largest Pyramid Constructed Jan 30, 1856 King Menes unites Upper and Lower Egypt 3100 BC Jan 30, 1958 James Mellaart discovers Neolithic farming village of Catalhuyuk Jan 30, 1960 Leakey team discovers Homo Habilis Jan 30, 1974 Johanson team discovers Lucy Jan 30, 1978 Leakey team discovers Laetoli footprints