Solon was a statesman in Athens elected after noblemen in the area had taken positions of power to support and benefit their individual areas. Wealthy landowners controlled large amounts of farmland and the people who worked it, and were able to use their names and wealth to adversely affect government in Athens, awarding their own regions while divesting others; an example of this was Laconia:

The effects of regionalism in a large territory could be seen in Laconia, where Sparta had gained control through intimidation and resettlement of some of its neighbours and enslavement of the rest. (eNotes wiki)

Solon was elected in a position of mediation and vast, previously unseen power to make rules and carry out justice. He ordained laws containing three specific reforms, inscribed on wooden cylinders at the Prytaneum, the everlasting fire that symbolized unity in each city-state. The three reforms are:

1. Constitutional: leaders were elected by decision by a body of past leaders, the Areopagus, whose decisions were final. Although middle-class citizens were allowed into the process, lower-class citizens were not. Solon allowed every citizen access to and a voice in decisions made in the court system; he also created four classes based on income, and although all citizens had a voice only the wealthy were allowed elective status. Many historians point to this as the birth of Pure Democracy.
2. Economic: since the vast majority of citizens lived a subsistence lifestyle -- they produced for themselves day by day -- there was little opportunity to collect and store wealth. In order to foster economic growth, Solon ordered: fathers to find trade for their sons, and if they could not, the sons had no obligation to support their fathers; citizenship to traders settling in Athens; olives to be the main product and all other grown export prohibited; and recalculation of weights and measures to be competitive and fair.
3. Moral: after forgiving all outstanding debts, Solon prohibited the use of indentured servitude as payment and freed all enslaved citizens. He also reformed systems of legal action,  and made it a crime to refuse military service. These reforms allowed non-wealthy citizens the same rights as the upper-class.

After these reforms were put into place, Solon retired, leaving the system to operate independently. It took very little time for abuses to appear, especially in government positions; there was no oversight and so lawmakers could use their authority as they saw fit. Eventually Solon's relative Peisistratus took control and instituted a tyranny that managed the existing laws and gained a measure of popularity.

Solon's reforms contain the roots of both Pure Democracy and Representative Democracy. In eliminating unfair divisions between classes, Solon was one of the first politicians to recognize and ordain that all citizens are equal under the law, even if they can not be guaranteed success.