He lived in Eisenach from 1685 to 1695 and in 1695  he moved in Ohrdruf where began to learn about organ building.
For a short time he lived in Lüneburg 1700-1702 and in 1703 he became violinist in the private orchestra of the prince at Weimar.
He  left within a year to become organist at Arnstadt where he worked from 1703 to 1707. Bach went to Mühlhausen,  where he was offered a more lucrative post as organist in 1707. Since 1703 at Arnstadt and Mühlhausen Bach was embarking on the serious composition of organ preludes. He wrote an elaborate, festive cantata —Gott ist mein König, BWV 71— for the inauguration of the new council in 1708.
In 1708 he was made court organist and chamber musician at Weimar. It was  his first major appointment and in 1714 he became there concert master. At Weimar (1708-1717) Bach wrote most of his composes for the organ: the Passacaglia and Fugue in C Minor, most of the great preludes and fugues, and the 45 chorale-preludes gathered in the little organ book Das Orgelbüchlein.
Prince Leopold of Anhalt engaged him as musical director at Köthen in 1717. This was followed by a six-year stay (1717 – 23) as kapellmeister at the princely court of Köthen.
In 1717 at Köthen he concentrated on instrumental compositions, especially keyboard works: the Chromatic Fantasy and Fugue; the English Suites; the French Suites; the Two-Part and Three-Part Inventions, written for the education of his son Wilhelm Friedemann; and Book I of the celebrated Well-Tempered Clavier (1722). The well-known Brandenburg concertos (2,4,5) (1711–20),  recognized as the best concerti grossi ever composed.
So-called Brandenburg Concertos were not written all at once, nor for the same ensemble. Scholars suspect that nos. 1, 3, and 6 may have been written much earlier than the others, perhaps dating from Bach's Weimar period (1708-1717), while 2, 4, and 5 most likely came from Cöthen. Bach later put the 6 concertos together and dedicated them to the margrave of Brandenburg, hoping to get a new job out of it.
In 1723 made his final move to Leipzig, where he took the important post of music director of the church of St. Thomas,  and of its choir school, with responsibility for music in the five principal city churches.
At Leipzig (1723-1750) he wrote The St. John Passion (1723) and more than 200 church cantatas. His orchestral works include four orchestral suites, and many harpsichord concertos, a genre he invented. His Magnificat (1723)   was presented shortly after he assumed that post.
Many more of his superb religious compositions followed: the St. Matthew Passion (1729), "The  High Mass, h-moll, " B Minor ((1733-1738, 1749),the Christmas Oratorio (1734) , and the six motets.
The principal keyboard works of this period were Book II of The Well-Tempered Clavier (1744). His last notable compositions were the Musical Offering composed (1747) for Frederick the Great and The Art of the Fugue (1749).

When he was nine he lost his mother, and a year later his father, so he was living with his oldest brother. 
He had an insatiable curiosity about music and sometimes walked great distances to hear the organists Johann Adam Reinken (at Hamburg) and Buxtehude (at Lübeck).
During his life he lived in different places and work there, theye are Eisenach 1685-1695, Ohrdruf 1695-1700, Lüneburg 1700-1702,  Weimar 1703,  Arnstadt 1703-1707,  Mühlhausen 1707-1708, Weimar 1708-1717,  Köthen 1717-1723,   Leipzig 1723-1750.
In 1707 he went to Mühlhausen, where he married his cousin Maria Barbara Bach, who was to bear him seven children, three of whom died in childhood.
Main reasons for relocation include: poor working conditions, dependent status, lack of creative freedom. Once in 1717, when Bach decided to take another job, the duke of Weimar had him arrested and jailed for a month.
In 1720 his wife died and in 1721 he married Anna Magdalena Wülken, 19 years old girl. She regularly helped him transcribe his music. Together they had 13 kids, six of whom survived into adulthood.
Bach fathered 20 children. His first wife Maria Barbara Bach to bear him seven children, three of whom died in childhood.  Second wife was Anna Magdalena Wülken,  and together they had 13 kids, six of whom survived into adulthood.
Some of his were also celebrated musicians. Four of Bach's sons were extremely musically gifted. The eldest of them, Wilhelm Friedemann (1710-1784), was an outstanding organist, a virtuoso not inferior to his father. Bach was the grandfather of noted composer Johann Christian Bach (1735-82) The name of Bach has become synonymous with urban musician in Germany. 
Despite the fact that Bach lived hard life full of hardships and losses, he remained a simple and kind person. He was smoking a pipe and liked beer and coffee.
"Coffee Cantata" was composed in a Zimmerman’s Coffee House.
During the last year, his eyesight began to decline and  in 1749 he had two operations to help his vision. He remained in Leipzig until his death on July 28, 1750.
Buried, Thomaskirche, Leipzig, Germany
Bach's name and works were soon forgotten. His wife, Anna Magdalena, and youngest daughter Regina died in poverty.