How did chinampas help the Aztec economy

Aztec agriculture in the heart of the empire used chinampas for their crops. Chinampa is a method of farming that used small, rectangular areas to grow crops on the shallow lake beds in the Mexican valley.  Chinampas were essentially artificial islands created for the crops.

An area was staked out in the lake bed, usually about thirty by two and a half meters.  Once the area was fenced off, the farmers layered it with mud, sediment, and decaying vegetation until it was above the level of the lake. Trees were also often planted in the corners to help secure the area.

These islands then provided rich soil for crops with easy access to water. The farmers used channels between the islands to get to each area by canoe.

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.

both are true, the congress does have the power to create banks, even if this power is not specifically described in the constitution, since there is nothing restricting it and there is power given to the congress to make "all laws which shall be necessary and proper". maryland was not allowed to tax a branch of the national bank operating there, and the supreme court decided that no state could. both of these topics were discussed in a decision of the mcculloch v. maryland case in 1819.