The assessed value is only a benchmark for calculations, and does not, in and of itself, mean that your taxes are too high. The assessment value is multiplied by the tax rate. Example: $600,000 (assessment) x .0150 (tax rate) = $9000 $500,000 (assessment) x .0185 (tax rate) = $9250 In the example, the property owner with the lower assessment actually has higher taxes.
What matters is how the assessment and taxes on your property compare to similar properties in your town. If the assessment on your property is higher than that of similar properties in your town, you may have grounds for a tax appeal.
If you had a REALTOR assist you in the purchase of your property, you could ask that REALTOR for tax data on properties in your town. Alternatively, that info is also available from the local town assessor's office. Evaluate your property against the comps to determine your next step.